<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  11.3.0.1 -->
<!--Based on XBRL 2.1-->
<!--Created on: 6/10/2026 11:04:43 PM-->
<!--Modified on: 6/10/2026 11:04:43 PM-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="msb-20260430.xsd#StatementCondensedStatementsOfIncome" roleURI="http://www.mesabi-trust.com/role/StatementCondensedStatementsOfIncome" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="msb-20260430.xsd#StatementCondensedBalanceSheets" roleURI="http://www.mesabi-trust.com/role/StatementCondensedBalanceSheets" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="msb-20260430.xsd#StatementCondensedStatementsOfCashFlows" roleURI="http://www.mesabi-trust.com/role/StatementCondensedStatementsOfCashFlows" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="msb-20260430.xsd#StatementStatementsOfCashFlowsCalc2" roleURI="http://www.mesabi-trust.com/role/StatementStatementsOfCashFlowsCalc2" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="msb-20260430.xsd#DisclosureUnallocatedReserveAndDistributionsDetails" roleURI="http://www.mesabi-trust.com/role/DisclosureUnallocatedReserveAndDistributionsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <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" />
  <calculationLink xlink:role="http://www.mesabi-trust.com/role/StatementCondensedStatementsOfIncome" xlink:type="extended" xlink:title="995200100 - Statement - Condensed Statements of Income" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_CostOfGoodsAndServicesSold_639167294833283320" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_Revenues_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_RoyaltiesIncomeLoss" xlink:label="msb_RoyaltiesIncomeLoss_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Revenues_639167294833283320" xlink:to="msb_RoyaltiesIncomeLoss_639167294833283320" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Revenues_639167294833283320" xlink:to="us-gaap_InterestIncomeExpenseNet_639167294833283320" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.mesabi-trust.com/role/StatementCondensedBalanceSheets" xlink:type="extended" xlink:title="995200200 - Statement - Condensed Balance Sheets" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AssetsCurrent_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639167294833283320" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommodityContractAssetCurrent" xlink:label="us-gaap_CommodityContractAssetCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639167294833283320" xlink:to="us-gaap_CommodityContractAssetCurrent_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639167294833283320" xlink:to="us-gaap_AccountsReceivableNetCurrent_639167294833283320" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639167294833283320" xlink:to="us-gaap_PrepaidExpenseCurrent_639167294833283320" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_FixedPropertyIncludingIntangible" xlink:label="msb_FixedPropertyIncludingIntangible_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="msb_FixedPropertyIncludingIntangible_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_AmendedAssignmentsOfLeaseProperty" xlink:label="msb_AmendedAssignmentsOfLeaseProperty_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="msb_FixedPropertyIncludingIntangible_639167294833283320" xlink:to="msb_AmendedAssignmentsOfLeaseProperty_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_AssignmentsOfLeasedProperty" xlink:label="msb_AssignmentsOfLeasedProperty_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="msb_FixedPropertyIncludingIntangible_639167294833283320" xlink:to="msb_AssignmentsOfLeasedProperty_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_CertificateOfBeneficialInterestLandTrust" xlink:label="msb_CertificateOfBeneficialInterestLandTrust_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="msb_FixedPropertyIncludingIntangible_639167294833283320" xlink:to="msb_CertificateOfBeneficialInterestLandTrust_639167294833283320" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_635484573067979207" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity_635484573067979207" xlink:to="us-gaap_Liabilities_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndDividendsPayableCurrent" xlink:label="us-gaap_InterestAndDividendsPayableCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities_639167294833283320" xlink:to="us-gaap_InterestAndDividendsPayableCurrent_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities_639167294833283320" xlink:to="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_UnallocatedReserve" xlink:label="msb_UnallocatedReserve_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity_635484573067979207" xlink:to="msb_UnallocatedReserve_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalUnits" xlink:label="us-gaap_CapitalUnits_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity_635484573067979207" xlink:to="us-gaap_CapitalUnits_639167294833283320" order="3" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.mesabi-trust.com/role/StatementCondensedStatementsOfCashFlows" xlink:type="extended" xlink:title="995200300 - Statement - Condensed Statements of Cash Flows" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromRoyaltiesReceived" xlink:label="us-gaap_ProceedsFromRoyaltiesReceived_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639167294833283320" xlink:to="us-gaap_ProceedsFromRoyaltiesReceived_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromInterestReceived" xlink:label="us-gaap_ProceedsFromInterestReceived_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639167294833283320" xlink:to="us-gaap_ProceedsFromInterestReceived_639167294833283320" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForOperatingActivities" xlink:label="us-gaap_PaymentsForOperatingActivities_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639167294833283320" xlink:to="us-gaap_PaymentsForOperatingActivities_639167294833283320" order="3" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividends" xlink:label="us-gaap_PaymentsOfDividends_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_PaymentsOfDividends_639167294833283320" order="2" use="optional" weight="-1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.mesabi-trust.com/role/StatementStatementsOfCashFlowsCalc2" xlink:type="extended" xlink:title="00401 - Statement - STATEMENTS OF CASH FLOWS(Calc2)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ProfitLoss_639167294833283320" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerAsset" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerAsset_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInContractWithCustomerAsset_639167294833283320" order="2" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_639167294833283320" order="3" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense_639167294833283320" order="4" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_639167294833283320" order="5" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.mesabi-trust.com/role/DisclosureUnallocatedReserveAndDistributionsDetails" xlink:type="extended" xlink:title="99940401 - Disclosure - UNALLOCATED RESERVE AND DISTRIBUTIONS (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_UnallocatedCashAndCashEquivalentsAndUSGovernmentSecurities" xlink:label="msb_UnallocatedCashAndCashEquivalentsAndUSGovernmentSecurities_635484597673059207" />
    <loc xlink:type="locator" xlink:href="msb-20260430.xsd#msb_CashAndCashEquivalentsAndUSGovernmentSecurities" xlink:label="msb_CashAndCashEquivalentsAndUSGovernmentSecurities_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="msb_UnallocatedCashAndCashEquivalentsAndUSGovernmentSecurities_635484597673059207" xlink:to="msb_CashAndCashEquivalentsAndUSGovernmentSecurities_639167294833283320" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndDividendsPayableCurrent" xlink:label="us-gaap_InterestAndDividendsPayableCurrent_639167294833283320" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="msb_UnallocatedCashAndCashEquivalentsAndUSGovernmentSecurities_635484597673059207" xlink:to="us-gaap_InterestAndDividendsPayableCurrent_639167294833283320" order="2" use="optional" weight="-1" />
  </calculationLink>
</link:linkbase>
