<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019fed12-0be0-7e63-ac14-5a214663be9f,g:cbdca485-0a22-4cea-971b-127b120a0e81-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.geron.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="gern-20260930.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7572-a20b-ee9ee3a8666c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7572-a20b-ee9ee3a8666c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7143-a52b-f37e7bd9c028" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7143-a52b-f37e7bd9c028" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent_019fed12-0c82-77c3-aef0-4693f2949e68" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent_019fed12-0c82-77c3-aef0-4693f2949e68" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019fed12-0c82-7681-8bc9-b796ad3f4ce1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019fed12-0c82-7681-8bc9-b796ad3f4ce1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NontradeReceivablesCurrent_019fed12-0c82-7311-a244-a99f5c804c5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NontradeReceivablesCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_NontradeReceivablesCurrent_019fed12-0c82-7311-a244-a99f5c804c5d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019fed12-0c82-7b9b-a106-de38ac04daf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_InventoryNet_019fed12-0c82-7b9b-a106-de38ac04daf0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019fed12-0c82-7cad-b478-5dab464d9f7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fed12-0c82-7f5f-ae00-199fa09c91d6" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019fed12-0c82-7cad-b478-5dab464d9f7f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019fed12-0c82-71bf-b8d7-b60190e542b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:to="loc_us-gaap_AssetsCurrent_019fed12-0c82-71bf-b8d7-b60190e542b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent_019fed12-0c82-76f0-9bc6-0a834e4b1ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent_019fed12-0c82-76f0-9bc6-0a834e4b1ce7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019fed12-0c82-71ef-b3b3-753705843aa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019fed12-0c82-71ef-b3b3-753705843aa2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019fed12-0c82-73ad-a081-5ef81bcde19f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019fed12-0c82-73ad-a081-5ef81bcde19f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_DepositsAndOtherAssetsNoncurrent_019fed12-0c82-779c-9c32-f69995c0badb" xlink:href="gern-20260930.xsd#gern_DepositsAndOtherAssetsNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fed12-0c82-7f42-bca0-526809f2d0dd" xlink:to="loc_gern_DepositsAndOtherAssetsNoncurrent_019fed12-0c82-779c-9c32-f69995c0badb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019fed12-0c82-7b73-bb07-8616f6b6a3db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:to="loc_us-gaap_AccountsPayableCurrent_019fed12-0c82-7b73-bb07-8616f6b6a3db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7cd6-908c-800ca950391e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7cd6-908c-800ca950391e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019fed12-0c82-7c90-a20c-8dde068c3d8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019fed12-0c82-7c90-a20c-8dde068c3d8c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_LiabilityRelatedToSaleOfFutureRoyaltiesCurrent_019fed12-0c82-7085-b3ce-95550b637d44" xlink:href="gern-20260930.xsd#gern_LiabilityRelatedToSaleOfFutureRoyaltiesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:to="loc_gern_LiabilityRelatedToSaleOfFutureRoyaltiesCurrent_019fed12-0c82-7085-b3ce-95550b637d44" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7f54-8031-f2f23401a7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-77ae-b714-507701747386" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7f54-8031-f2f23401a7c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019fed12-0c82-75ad-af19-87b8be7aa028" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-746e-8ad6-7edf1cc4c80c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fed12-0c82-75ad-af19-87b8be7aa028" xlink:to="loc_us-gaap_LiabilitiesCurrent_019fed12-0c82-746e-8ad6-7edf1cc4c80c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019fed12-0c82-7774-85a9-3cac845a0085" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fed12-0c82-75ad-af19-87b8be7aa028" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019fed12-0c82-7774-85a9-3cac845a0085" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_LiabilityRelatedToSaleOfFutureRoyaltiesNoncurrent_019fed12-0c82-7be6-bc5e-c44dbc7894ec" xlink:href="gern-20260930.xsd#gern_LiabilityRelatedToSaleOfFutureRoyaltiesNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fed12-0c82-75ad-af19-87b8be7aa028" xlink:to="loc_gern_LiabilityRelatedToSaleOfFutureRoyaltiesNoncurrent_019fed12-0c82-7be6-bc5e-c44dbc7894ec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0c82-7117-92dc-e46c16543426" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fed12-0c82-75ad-af19-87b8be7aa028" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0c82-7117-92dc-e46c16543426" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019fed12-0c82-78be-bb2e-89c20b93f609" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:to="loc_us-gaap_PreferredStockValue_019fed12-0c82-78be-bb2e-89c20b93f609" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019fed12-0c82-7668-94b4-23dd7325fa57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:to="loc_us-gaap_CommonStockValue_019fed12-0c82-7668-94b4-23dd7325fa57" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019fed12-0c82-712b-9421-6af9cc4a6b53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019fed12-0c82-712b-9421-6af9cc4a6b53" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019fed12-0c82-74a3-9f7a-7551941d4bc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019fed12-0c82-74a3-9f7a-7551941d4bc6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019fed12-0c82-7a5d-8823-9da2c5aac96d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019fed12-0c82-74b7-a7a0-20cb4a88744f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019fed12-0c82-7a5d-8823-9da2c5aac96d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fed12-0c82-77d4-9646-a541d26072e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019fed12-0c82-7938-ae3f-3a2d31779b9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fed12-0c82-77d4-9646-a541d26072e4" xlink:to="loc_us-gaap_Liabilities_019fed12-0c82-7938-ae3f-3a2d31779b9f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019fed12-0c82-79ce-8d86-7a11e25be463" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fed12-0c82-77d4-9646-a541d26072e4" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019fed12-0c82-79ce-8d86-7a11e25be463" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fed12-0c82-7305-8054-3c88e46611eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fed12-0c82-77d4-9646-a541d26072e4" xlink:to="loc_us-gaap_StockholdersEquity_019fed12-0c82-7305-8054-3c88e46611eb" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="gern-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7913-a56a-d288dddca128" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fed12-0c82-7f1f-b464-dbcb9001684b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7913-a56a-d288dddca128" xlink:to="loc_us-gaap_OperatingIncomeLoss_019fed12-0c82-7f1f-b464-dbcb9001684b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019fed12-0c82-7c43-9475-0dc31d59d555" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7913-a56a-d288dddca128" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019fed12-0c82-7c43-9475-0dc31d59d555" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fed12-0c82-7340-a398-f54d65ca69d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7913-a56a-d288dddca128" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fed12-0c82-7340-a398-f54d65ca69d7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019fed12-0c82-7c38-a8e5-32a41ee9c375" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7913-a56a-d288dddca128" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019fed12-0c82-7c38-a8e5-32a41ee9c375" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fed12-0c82-7b8f-aaea-b1e7fd461ade" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fed12-0c82-7056-8844-d586cc5edb8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019fed12-0c82-7b8f-aaea-b1e7fd461ade" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fed12-0c82-7056-8844-d586cc5edb8a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019fed12-0c82-722d-be80-c6591376b01e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019fed12-0c82-7b8f-aaea-b1e7fd461ade" xlink:to="loc_us-gaap_OperatingExpenses_019fed12-0c82-722d-be80-c6591376b01e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingCostsAndExpenses_019fed12-0c82-7285-8b52-3b9f753d0ffd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingCostsAndExpenses"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:to="loc_us-gaap_OperatingCostsAndExpenses_019fed12-0c82-7285-8b52-3b9f753d0ffd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019fed12-0c82-765b-8486-45c07c25a277" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019fed12-0c82-765b-8486-45c07c25a277" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fed12-0c82-791e-98ba-1c1a33f819b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fed12-0c82-791e-98ba-1c1a33f819b7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a17977-d6ca-7be0-8afa-e28a38705259" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a17977-d6ca-7be0-8afa-e28a38705259" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019fed12-0c82-7342-9ec6-6474e07f0384" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019fed12-0c82-7736-a992-6cd905b6e241" xlink:to="loc_us-gaap_RestructuringCharges_019fed12-0c82-7342-9ec6-6474e07f0384" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="simple" xlink:href="gern-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019fed12-0c82-77b1-96c9-dcb82f9d8b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7027-bd78-4a24a0b5e76c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019fed12-0c82-77b1-96c9-dcb82f9d8b1e" xlink:to="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7027-bd78-4a24a0b5e76c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_019fed12-0c82-788f-a47e-4d05e01e9e21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019fed12-0c82-77b1-96c9-dcb82f9d8b1e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_019fed12-0c82-788f-a47e-4d05e01e9e21" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019fed12-0c82-757b-a047-6322139cb0cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019fed12-0c82-77b1-96c9-dcb82f9d8b1e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019fed12-0c82-757b-a047-6322139cb0cc" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="gern-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fed12-0c82-7f85-a2e8-4cf356a92320" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7ec6-912f-a951399d808a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fed12-0c82-7f85-a2e8-4cf356a92320" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7ec6-912f-a951399d808a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-72b7-b418-2b805dbc7e55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fed12-0c82-7f85-a2e8-4cf356a92320" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-72b7-b418-2b805dbc7e55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7c96-8f85-72951ef725f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fed12-0c82-7f85-a2e8-4cf356a92320" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7c96-8f85-72951ef725f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019fed12-0c82-7276-a980-5fa0e51eadaf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fed12-0c82-7f85-a2e8-4cf356a92320" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019fed12-0c82-7276-a980-5fa0e51eadaf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7355-b6ef-15107d226efc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_019fed12-0c82-7186-92c0-0ecb8c8879ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7355-b6ef-15107d226efc" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_019fed12-0c82-7186-92c0-0ecb8c8879ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromWarrantExercises_019fed12-0c82-7f1f-8170-4775110de139" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromWarrantExercises"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7355-b6ef-15107d226efc" xlink:to="loc_us-gaap_ProceedsFromWarrantExercises_019fed12-0c82-7f1f-8170-4775110de139" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockPlans_019fed12-0c82-75a3-8895-1632e7624f48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromStockPlans"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fed12-0c82-7355-b6ef-15107d226efc" xlink:to="loc_us-gaap_ProceedsFromStockPlans_019fed12-0c82-75a3-8895-1632e7624f48" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-7518-ac69-ed73b1f245bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_PaymentsUnpaidToAcquirePropertyPlantAndEquipment_019fed12-0c82-7185-aa16-e442bcb2f81f" xlink:href="gern-20260930.xsd#gern_PaymentsUnpaidToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-7518-ac69-ed73b1f245bd" xlink:to="loc_gern_PaymentsUnpaidToAcquirePropertyPlantAndEquipment_019fed12-0c82-7185-aa16-e442bcb2f81f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireMarketableSecurities_019fed12-0c82-7cfc-a9b1-55792dd92212" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireMarketableSecurities"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-7518-ac69-ed73b1f245bd" xlink:to="loc_us-gaap_PaymentsToAcquireMarketableSecurities_019fed12-0c82-7cfc-a9b1-55792dd92212" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_019fed12-0c82-786d-a5bc-32443a78b1ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fed12-0c82-7518-ac69-ed73b1f245bd" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_019fed12-0c82-786d-a5bc-32443a78b1ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7e6f-b475-7110c29b28ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_NetIncomeLoss_019fed12-0c82-7e6f-b475-7110c29b28ed" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019fed12-0c82-7dfc-b3ba-b595983db2ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_DepreciationAndAmortization_019fed12-0c82-7dfc-b3ba-b595983db2ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019fed12-0c82-7e2d-b0d7-747f633c002a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019fed12-0c82-7e2d-b0d7-747f633c002a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019fed12-0c82-7dce-8796-764728c5891b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019fed12-0c82-7dce-8796-764728c5891b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_NoncashInterestExpenseOnLiabilitiesForSalesOfFutureRoyalties_019fed12-0c82-7505-a59c-36f58b1d4c0c" xlink:href="gern-20260930.xsd#gern_NoncashInterestExpenseOnLiabilitiesForSalesOfFutureRoyalties"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_gern_NoncashInterestExpenseOnLiabilitiesForSalesOfFutureRoyalties_019fed12-0c82-7505-a59c-36f58b1d4c0c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWriteDown_019fed12-0c82-7586-aae2-3f304163130d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryWriteDown"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_InventoryWriteDown_019fed12-0c82-7586-aae2-3f304163130d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019fed12-0c82-76ae-a3d5-885387481d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_ShareBasedCompensation_019fed12-0c82-76ae-a3d5-885387481d7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019fed12-0c82-7138-ae1e-8dd9a99000e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019fed12-0c82-7138-ae1e-8dd9a99000e6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_IncreaseDecreaseInAllowanceForDoubtfulAccounts_019fed12-0c82-7ce4-83d2-ba983bcf6a5f" xlink:href="gern-20260930.xsd#gern_IncreaseDecreaseInAllowanceForDoubtfulAccounts"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_gern_IncreaseDecreaseInAllowanceForDoubtfulAccounts_019fed12-0c82-7ce4-83d2-ba983bcf6a5f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_019fed12-0c82-7cc1-adac-ae7bc0fa823e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_019fed12-0c82-7cc1-adac-ae7bc0fa823e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019fed12-0c82-7968-894e-622c7d647f41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019fed12-0c82-7968-894e-622c7d647f41" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019fed12-0c82-794c-80f1-11eab1b13710" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019fed12-0c82-794c-80f1-11eab1b13710" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019fed12-0c82-71d5-b267-683f004d6ed5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019fed12-0c82-71d5-b267-683f004d6ed5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019fed12-0c82-7e7d-b82f-484d60a6a76a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019fed12-0c82-7e7d-b82f-484d60a6a76a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherAccruedLiabilities_019fed12-0c82-76f7-94bc-ab8bb6810a37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherAccruedLiabilities"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherAccruedLiabilities_019fed12-0c82-76f7-94bc-ab8bb6810a37" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRoyalties_019fed12-0c82-7775-9e68-d2a57a42a6e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRoyalties"/>
    <link:calculationArc order="16" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_us-gaap_PaymentsForRoyalties_019fed12-0c82-7775-9e68-d2a57a42a6e1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_IncreaseDecreaseInOperatingLeaseLiabilities_019fed12-0c82-7ace-9dad-78defcf20bff" xlink:href="gern-20260930.xsd#gern_IncreaseDecreaseInOperatingLeaseLiabilities"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fed12-0c82-7822-8ef1-17ed7c367c7e" xlink:to="loc_gern_IncreaseDecreaseInOperatingLeaseLiabilities_019fed12-0c82-7ace-9dad-78defcf20bff" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/INVENTORYDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#INVENTORYDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/INVENTORYDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019fed12-0c82-7105-9c3d-3fbfb29dae2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019fed12-0c82-7647-8d2c-73c01bdc9ae3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryRawMaterialsNetOfReserves"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019fed12-0c82-7105-9c3d-3fbfb29dae2c" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019fed12-0c82-7647-8d2c-73c01bdc9ae3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019fed12-0c82-7643-960d-73890de25fe9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryWorkInProcessNetOfReserves"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019fed12-0c82-7105-9c3d-3fbfb29dae2c" xlink:to="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019fed12-0c82-7643-960d-73890de25fe9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019fed12-0c82-7665-820d-3fa8dadeb523" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019fed12-0c82-7105-9c3d-3fbfb29dae2c" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019fed12-0c82-7665-820d-3fa8dadeb523" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/FINANCIALINSTRUMENTSScheduleofCashEquivalentsRestrictedCashandMarketableSecuritiesDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#FINANCIALINSTRUMENTSScheduleofCashEquivalentsRestrictedCashandMarketableSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/FINANCIALINSTRUMENTSScheduleofCashEquivalentsRestrictedCashandMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019fed12-0c82-7be5-a6c6-c4e10f7b12b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019fed12-0c82-79ab-b0f3-2f84026fa650" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019fed12-0c82-7be5-a6c6-c4e10f7b12b1" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019fed12-0c82-79ab-b0f3-2f84026fa650" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019fed12-0c82-7b12-9892-9e25ac02ded4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019fed12-0c82-7be5-a6c6-c4e10f7b12b1" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019fed12-0c82-7b12-9892-9e25ac02ded4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019fed12-0c82-75bc-a803-8df79c098533" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019fed12-0c82-7be5-a6c6-c4e10f7b12b1" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019fed12-0c82-75bc-a803-8df79c098533" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7565-9f86-2e646683d65b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_RestrictedCashAndCashEquivalentsGrossUnrealizedGains_019fed12-0c82-7ac8-a3f4-053575656491" xlink:href="gern-20260930.xsd#gern_RestrictedCashAndCashEquivalentsGrossUnrealizedGains"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7565-9f86-2e646683d65b" xlink:to="loc_gern_RestrictedCashAndCashEquivalentsGrossUnrealizedGains_019fed12-0c82-7ac8-a3f4-053575656491" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_RestrictedCashAndCashEquivalentsGrossUnrealizedLosses_019fed12-0c82-7d28-bbf3-6c3eaf7aa575" xlink:href="gern-20260930.xsd#gern_RestrictedCashAndCashEquivalentsGrossUnrealizedLosses"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7565-9f86-2e646683d65b" xlink:to="loc_gern_RestrictedCashAndCashEquivalentsGrossUnrealizedLosses_019fed12-0c82-7d28-bbf3-6c3eaf7aa575" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedInvestmentsAtFairValue_019fed12-0c82-78ed-9382-6372d23872fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedInvestmentsAtFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7565-9f86-2e646683d65b" xlink:to="loc_us-gaap_RestrictedInvestmentsAtFairValue_019fed12-0c82-78ed-9382-6372d23872fe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashEquivalentsAtCarryingValue_019fed12-0c82-7ecb-918f-3acfe120e89a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashEquivalentsAtCarryingValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_CashAndCashEquivalentsUnrealizedLosses_019fed12-0c82-78bb-9765-b166a8cfa20b" xlink:href="gern-20260930.xsd#gern_CashAndCashEquivalentsUnrealizedLosses"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashEquivalentsAtCarryingValue_019fed12-0c82-7ecb-918f-3acfe120e89a" xlink:to="loc_gern_CashAndCashEquivalentsUnrealizedLosses_019fed12-0c82-78bb-9765-b166a8cfa20b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fed12-0c82-7244-8729-ac4995f5cb08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashEquivalentsAtCarryingValue_019fed12-0c82-7ecb-918f-3acfe120e89a" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fed12-0c82-7244-8729-ac4995f5cb08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_CashAndCashEquivalentsUnrealizedGains_019fed12-0c82-7dff-80b0-146ff7181574" xlink:href="gern-20260930.xsd#gern_CashAndCashEquivalentsUnrealizedGains"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashEquivalentsAtCarryingValue_019fed12-0c82-7ecb-918f-3acfe120e89a" xlink:to="loc_gern_CashAndCashEquivalentsUnrealizedGains_019fed12-0c82-7dff-80b0-146ff7181574" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/FINANCIALINSTRUMENTSScheduleofCashEquivalentsandMarketableSecuritieswithUnrealizedLossesDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#FINANCIALINSTRUMENTSScheduleofCashEquivalentsandMarketableSecuritieswithUnrealizedLossesDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/FINANCIALINSTRUMENTSScheduleofCashEquivalentsandMarketableSecuritieswithUnrealizedLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019fed12-0c82-7f0d-9af2-abe3f9ef8fe8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019fed12-0c82-73bb-a451-12323b625c71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019fed12-0c82-7f0d-9af2-abe3f9ef8fe8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019fed12-0c82-73bb-a451-12323b625c71" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019fed12-0c82-78b7-9a36-47a6fde577ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019fed12-0c82-7f0d-9af2-abe3f9ef8fe8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019fed12-0c82-78b7-9a36-47a6fde577ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019fed12-0c82-75af-92ce-c50214d93dc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019fed12-0c82-7998-b62b-d0495cd1768a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019fed12-0c82-75af-92ce-c50214d93dc2" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019fed12-0c82-7998-b62b-d0495cd1768a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019fed12-0c82-7ff8-a55d-f338c4e57ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019fed12-0c82-75af-92ce-c50214d93dc2" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019fed12-0c82-7ff8-a55d-f338c4e57ca9" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#FAIRVALUEMEASUREMENTSDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019fed12-0c82-7507-ab64-f4a5ef783f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure_019fed12-0c82-78c6-b94b-c3beec762784" xlink:href="gern-20260930.xsd#gern_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019fed12-0c82-7507-ab64-f4a5ef783f0e" xlink:to="loc_gern_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure_019fed12-0c82-78c6-b94b-c3beec762784" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019fed12-0c82-702d-921b-9a18edac188d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019fed12-0c82-7507-ab64-f4a5ef783f0e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019fed12-0c82-702d-921b-9a18edac188d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019fed12-0c82-7ef6-9b13-0bedf5e9eb17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedRoyaltiesCurrentAndNoncurrent_019fed12-0c82-7477-9458-dd33feca5ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedRoyaltiesCurrentAndNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_019fed12-0c82-7ef6-9b13-0bedf5e9eb17" xlink:to="loc_us-gaap_AccruedRoyaltiesCurrentAndNoncurrent_019fed12-0c82-7477-9458-dd33feca5ac2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedLiabilitiesDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_AccruedClinicalResearchOrganizationsAndClinicalTrialCostsCurrent_019fed12-0c82-7462-9177-0ada4e37fd16" xlink:href="gern-20260930.xsd#gern_AccruedClinicalResearchOrganizationsAndClinicalTrialCostsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_gern_AccruedClinicalResearchOrganizationsAndClinicalTrialCostsCurrent_019fed12-0c82-7462-9177-0ada4e37fd16" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_AccruedManufacturingActivitiesCurrent_019fed12-0c82-711a-8e79-4d10531d91a1" xlink:href="gern-20260930.xsd#gern_AccruedManufacturingActivitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_gern_AccruedManufacturingActivitiesCurrent_019fed12-0c82-711a-8e79-4d10531d91a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedProfessionalFeesCurrent_019fed12-0c82-7870-ac00-efc5c9d6e513" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedProfessionalFeesCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_us-gaap_AccruedProfessionalFeesCurrent_019fed12-0c82-7870-ac00-efc5c9d6e513" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPayableCurrent_019fed12-0c82-7c07-aa37-55ad75e4e590" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPayableCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_us-gaap_InterestPayableCurrent_019fed12-0c82-7c07-aa37-55ad75e4e590" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_GrossToNetAdjustmentsCurrent_019fed12-0c82-76cb-bea6-38d68b3b45de" xlink:href="gern-20260930.xsd#gern_GrossToNetAdjustmentsCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_gern_GrossToNetAdjustmentsCurrent_019fed12-0c82-76cb-bea6-38d68b3b45de" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019fed12-0c82-7675-a80a-0208c8ad1d33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAccruedLiabilitiesCurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019fed12-0c82-7755-978b-331eacfea61f" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019fed12-0c82-7675-a80a-0208c8ad1d33" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedCompensationandBenefitsDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedCompensationandBenefitsDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofAccruedCompensationandBenefitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7a2c-bc6c-7acda1d7a272" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedBonusesCurrent_019fed12-0c82-73c1-90fc-bdc6ba9169aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedBonusesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7a2c-bc6c-7acda1d7a272" xlink:to="loc_us-gaap_AccruedBonusesCurrent_019fed12-0c82-73c1-90fc-bdc6ba9169aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedVacationCurrent_019fed12-0c82-7bc8-be19-82b4ddea7aba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedVacationCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7a2c-bc6c-7acda1d7a272" xlink:to="loc_us-gaap_AccruedVacationCurrent_019fed12-0c82-7bc8-be19-82b4ddea7aba" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveCurrent_019fed12-0c82-719f-9d82-e196b2dfa65d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7a2c-bc6c-7acda1d7a272" xlink:to="loc_us-gaap_RestructuringReserveCurrent_019fed12-0c82-719f-9d82-e196b2dfa65d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherEmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7eb8-af44-b79ccc001a00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherEmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7a2c-bc6c-7acda1d7a272" xlink:to="loc_us-gaap_OtherEmployeeRelatedLiabilitiesCurrent_019fed12-0c82-7eb8-af44-b79ccc001a00" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofCashCashEquivalentsandRestrictedCashDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofCashCashEquivalentsandRestrictedCashDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/OTHERCONDENSEDCONSOLIDATEDFINANCIALSTATEMENTDETAILSScheduleofCashCashEquivalentsandRestrictedCashDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019fed12-0c82-796d-9dc4-f85ed7b1d633" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7368-a42d-5c3af567a0ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019fed12-0c82-796d-9dc4-f85ed7b1d633" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fed12-0c82-7368-a42d-5c3af567a0ab" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-74eb-9241-2199c5e17760" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019fed12-0c82-796d-9dc4-f85ed7b1d633" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue_019fed12-0c82-74eb-9241-2199c5e17760" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/DEBTScheduleofFutureMinimumPaymentsUnderLoanAgreementDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#DEBTScheduleofFutureMinimumPaymentsUnderLoanAgreementDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/DEBTScheduleofFutureMinimumPaymentsUnderLoanAgreementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0d30-7cd9-b9df-9615c9afc6b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7a06-a0a8-3ffae7daa747" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0d30-7cd9-b9df-9615c9afc6b7" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7a06-a0a8-3ffae7daa747" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedCapitalizedInterestCosts_019fed12-0d30-7417-bfc4-0cacf9e4d019" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedCapitalizedInterestCosts"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0d30-7cd9-b9df-9615c9afc6b7" xlink:to="loc_us-gaap_AccumulatedCapitalizedInterestCosts_019fed12-0d30-7417-bfc4-0cacf9e4d019" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019fed12-0d30-75d6-bbae-ba9aa5060084" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebtNoncurrent_019fed12-0d30-7cd9-b9df-9615c9afc6b7" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019fed12-0d30-75d6-bbae-ba9aa5060084" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019fed12-0d30-71f8-ac3d-b36cf8d780f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019fed12-0d30-71f8-ac3d-b36cf8d780f2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019fed12-0d30-7195-8df3-e7ccf478063f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019fed12-0d30-7195-8df3-e7ccf478063f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019fed12-0d30-7e66-a17b-59ee579a9a52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019fed12-0d30-7e66-a17b-59ee579a9a52" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019fed12-0d30-75f2-a22f-09644e73846b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019fed12-0d30-75f2-a22f-09644e73846b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gern_LongTermDebtMaturityAfterYearThree_019fed12-0d30-7a7c-87bd-3ac14dba4079" xlink:href="gern-20260930.xsd#gern_LongTermDebtMaturityAfterYearThree"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019fed12-0d30-7fa7-82e8-7166157e2665" xlink:to="loc_gern_LongTermDebtMaturityAfterYearThree_019fed12-0d30-7a7c-87bd-3ac14dba4079" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/NETINCOMELOSSPERCOMMONSHAREScheduleofBasicandDilutiveNetIncomeLossperShareDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#NETINCOMELOSSPERCOMMONSHAREScheduleofBasicandDilutiveNetIncomeLossperShareDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/NETINCOMELOSSPERCOMMONSHAREScheduleofBasicandDilutiveNetIncomeLossperShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a177b4-deb8-7127-b5be-f8ac22b38057" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_01a177b4-deb8-75e4-8338-37211f5a4dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a177b4-deb8-7127-b5be-f8ac22b38057" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_01a177b4-deb8-75e4-8338-37211f5a4dc6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_01a177b4-deb8-7ca7-baae-72988dd80486" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a177b4-deb8-7127-b5be-f8ac22b38057" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_01a177b4-deb8-7ca7-baae-72988dd80486" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.geron.com/role/SEGMENTREPORTINGDetails" xlink:type="simple" xlink:href="gern-20260930.xsd#SEGMENTREPORTINGDetails"/>
  <link:calculationLink xlink:role="http://www.geron.com/role/SEGMENTREPORTINGDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fed12-0d30-7729-b7d4-09b282211d54" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fed12-0d30-7729-b7d4-09b282211d54" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingCostsAndExpenses_019fed12-0d30-74e5-88f5-c0f7028b9e89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingCostsAndExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_OperatingCostsAndExpenses_019fed12-0d30-74e5-88f5-c0f7028b9e89" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019fed12-0d30-708b-910d-66624b5d7682" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019fed12-0d30-708b-910d-66624b5d7682" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fed12-0d30-7545-b4b7-68d44a4a6659" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fed12-0d30-7545-b4b7-68d44a4a6659" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a168f7-e76b-7afd-b038-34380ddce1a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a168f7-e76b-7afd-b038-34380ddce1a7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_01a0e75b-0575-7f5c-b478-9ae038f59f96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_OperatingExpenses_01a0e75b-0575-7f5c-b478-9ae038f59f96" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_01a0e75b-0575-7816-9fef-c70db77b85b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_OperatingIncomeLoss_01a0e75b-0575-7816-9fef-c70db77b85b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019fed12-0d30-7599-b34b-2efaf3458ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fed12-0d30-7eee-9424-308a9bb1f8fb" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019fed12-0d30-7599-b34b-2efaf3458ca3" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
