<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 6.5a -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" 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">
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#Cover" roleURI="http://mdb.com/role/Cover" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#BalanceSheets" roleURI="http://mdb.com/role/BalanceSheets" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#BalanceSheetsParenthetical" roleURI="http://mdb.com/role/BalanceSheetsParenthetical" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#StatementsOfOperations" roleURI="http://mdb.com/role/StatementsOfOperations" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#StatementsOfChangesInEquity" roleURI="http://mdb.com/role/StatementsOfChangesInEquity" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#StatementsOfCashFlows" roleURI="http://mdb.com/role/StatementsOfCashFlows" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#StatementsOfCashFlowsSupplementalDisclosures" roleURI="http://mdb.com/role/StatementsOfCashFlowsSupplementalDisclosures" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#OrganizationAndDescriptionOfBusiness" roleURI="http://mdb.com/role/OrganizationAndDescriptionOfBusiness" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SummaryOfSignificantAccountingPolicies" roleURI="http://mdb.com/role/SummaryOfSignificantAccountingPolicies" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SegmentReporting" roleURI="http://mdb.com/role/SegmentReporting" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityAndNon-controllingInterests" roleURI="http://mdb.com/role/EquityAndNon-controllingInterests" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityMethodInvestment" roleURI="http://mdb.com/role/EquityMethodInvestment" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#Stock-basedCompensation" roleURI="http://mdb.com/role/Stock-basedCompensation" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EarningsPerShare" roleURI="http://mdb.com/role/EarningsPerShare" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#RelatedPartyTransactions" roleURI="http://mdb.com/role/RelatedPartyTransactions" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#CommitmentsAndContingencies" roleURI="http://mdb.com/role/CommitmentsAndContingencies" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EmployeeBenefitPlans" roleURI="http://mdb.com/role/EmployeeBenefitPlans" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ExclusiveLicenseAgreementMdbMinnesotaOne" roleURI="http://mdb.com/role/ExclusiveLicenseAgreementMdbMinnesotaOne" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#Leases" roleURI="http://mdb.com/role/Leases" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#IncomeTaxes" roleURI="http://mdb.com/role/IncomeTaxes" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SubsequentEvents" roleURI="http://mdb.com/role/SubsequentEvents" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SummaryOfSignificantAccountingPoliciesPolicies" roleURI="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesPolicies" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SummaryOfSignificantAccountingPoliciesTables" roleURI="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SegmentReportingTables" roleURI="http://mdb.com/role/SegmentReportingTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityAndNon-controllingInterestsTables" roleURI="http://mdb.com/role/EquityAndNon-controllingInterestsTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityMethodInvestmentTables" roleURI="http://mdb.com/role/EquityMethodInvestmentTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#Stock-basedCompensationTables" roleURI="http://mdb.com/role/Stock-basedCompensationTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EarningsPerShareTables" roleURI="http://mdb.com/role/EarningsPerShareTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#LeasesTables" roleURI="http://mdb.com/role/LeasesTables" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#OrganizationAndDescriptionOfBusinessDetailsNarrative" roleURI="http://mdb.com/role/OrganizationAndDescriptionOfBusinessDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SummaryOfSignificantAccountingPoliciesDetailsNarrative" roleURI="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfInvestmentSecuritiesBrokerDealerDetails" roleURI="http://mdb.com/role/ScheduleOfInvestmentSecuritiesBrokerDealerDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfInvestmentSecuritiesNon-brokerDealerDetails" roleURI="http://mdb.com/role/ScheduleOfInvestmentSecuritiesNon-brokerDealerDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" roleURI="http://mdb.com/role/ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfReconciliationOfFairValueMeasurementsWithinLevel3OfFairValueHierarchyDetails" roleURI="http://mdb.com/role/ScheduleOfReconciliationOfFairValueMeasurementsWithinLevel3OfFairValueHierarchyDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfSignificantUnobservableInputsRelatedToMaterialComponentsOfLevel3WarrantsDetails" roleURI="http://mdb.com/role/ScheduleOfSignificantUnobservableInputsRelatedToMaterialComponentsOfLevel3WarrantsDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentDetails" roleURI="http://mdb.com/role/ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfPropertyAndEquipmentDetails" roleURI="http://mdb.com/role/ScheduleOfPropertyAndEquipmentDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfLong-livedAssetsAndTotalAssetsBySegmentDetails" roleURI="http://mdb.com/role/ScheduleOfLong-livedAssetsAndTotalAssetsBySegmentDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfStatementOfOperationBySegmentDetails" roleURI="http://mdb.com/role/ScheduleOfStatementOfOperationBySegmentDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SegmentReportingDetailsNarrative" roleURI="http://mdb.com/role/SegmentReportingDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfEquityAndNon-controllingInterestsDetails" roleURI="http://mdb.com/role/ScheduleOfEquityAndNon-controllingInterestsDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityAndNon-controllingInterestsDetailsNarrative" roleURI="http://mdb.com/role/EquityAndNon-controllingInterestsDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfEquityMethodInvestmentDetails" roleURI="http://mdb.com/role/ScheduleOfEquityMethodInvestmentDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EquityMethodInvestmentDetailsNarrative" roleURI="http://mdb.com/role/EquityMethodInvestmentDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfRestrictedStockUnitActivityDetails" roleURI="http://mdb.com/role/ScheduleOfRestrictedStockUnitActivityDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfTime-basedStockOptionActivityDetails" roleURI="http://mdb.com/role/ScheduleOfTime-basedStockOptionActivityDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfMarket-basedStockOptionActivityDetails" roleURI="http://mdb.com/role/ScheduleOfMarket-basedStockOptionActivityDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#Stock-basedCompensationDetailsNarrative" roleURI="http://mdb.com/role/Stock-basedCompensationDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfBasicAndFullyDilutedDetails" roleURI="http://mdb.com/role/ScheduleOfBasicAndFullyDilutedDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#RelatedPartyTransactionsDetailsNarrative" roleURI="http://mdb.com/role/RelatedPartyTransactionsDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#CommitmentsAndContingenciesDetailsNarrative" roleURI="http://mdb.com/role/CommitmentsAndContingenciesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#EmployeeBenefitPlansDetailsNarrative" roleURI="http://mdb.com/role/EmployeeBenefitPlansDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ExclusiveLicenseAgreementMdbMinnesotaOneDetailsNarrative" roleURI="http://mdb.com/role/ExclusiveLicenseAgreementMdbMinnesotaOneDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfOperatingLeaseCostDetails" roleURI="http://mdb.com/role/ScheduleOfOperatingLeaseCostDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#ScheduleOfFuturePaymentsDueUnderOperatingLeaseDetails" roleURI="http://mdb.com/role/ScheduleOfFuturePaymentsDueUnderOperatingLeaseDetails" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#LeasesDetailsNarrative" roleURI="http://mdb.com/role/LeasesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#IncomeTaxesDetailsNarrative" roleURI="http://mdb.com/role/IncomeTaxesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="mdbh-20260630.xsd#SubsequentEventsDetailsNarrative" roleURI="http://mdb.com/role/SubsequentEventsDetailsNarrative" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/Cover" xlink:title="00000001 - Document - Cover" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/BalanceSheets" xlink:title="00000002 - Statement - Condensed Consolidated Balance Sheets">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets" xlink:label="loc_us-gaapAssets" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndSecuritiesSegregatedUnderSecuritiesExchangeCommissionRegulation" xlink:label="loc_us-gaapCashAndSecuritiesSegregatedUnderSecuritiesExchangeCommissionRegulation" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapCashAndSecuritiesSegregatedUnderSecuritiesExchangeCommissionRegulation" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNet" xlink:label="loc_us-gaapAccountsReceivableNet" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapAccountsReceivableNet" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherReceivables" xlink:label="loc_us-gaapOtherReceivables" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapOtherReceivables" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsAssets" xlink:label="loc_us-gaapDepositsAssets" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapDepositsAssets" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaapPrepaidExpenseAndOtherAssetsCurrent" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapPrepaidExpenseAndOtherAssetsCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_InvestmentSecuritiesAtFairValueHeldByLicensedBrokerDealer" xlink:label="loc_MDBHInvestmentSecuritiesAtFairValueHeldByLicensedBrokerDealer" />
      <link:calculationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_MDBHInvestmentSecuritiesAtFairValueHeldByLicensedBrokerDealer" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_InvestmentSecuritiesAtFairValueHeldByNonlicensedBrokerDealer" xlink:label="loc_MDBHInvestmentSecuritiesAtFairValueHeldByNonlicensedBrokerDealer" />
      <link:calculationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_MDBHInvestmentSecuritiesAtFairValueHeldByNonlicensedBrokerDealer" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments" xlink:label="loc_us-gaapEquityMethodInvestments" />
      <link:calculationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapEquityMethodInvestments" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCosts" xlink:label="loc_us-gaapDeferredCosts" />
      <link:calculationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapDeferredCosts" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaapPropertyPlantAndEquipmentNet" />
      <link:calculationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapPropertyPlantAndEquipmentNet" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaapOperatingLeaseRightOfUseAsset" />
      <link:calculationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapOperatingLeaseRightOfUseAsset" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaapLiabilities" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:label="loc_us-gaapAccountsPayableCurrentAndNoncurrent" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapAccountsPayableCurrentAndNoncurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaapAccruedLiabilitiesCurrentAndNoncurrent" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapAccruedLiabilitiesCurrentAndNoncurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilities" xlink:label="loc_us-gaapOtherLiabilities" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapOtherLiabilities" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_PayablesToCustomersCurrentAndNonCurrent" xlink:label="loc_MDBHPayablesToCustomersCurrentAndNonCurrent" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_MDBHPayablesToCustomersCurrentAndNonCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiability" xlink:label="loc_us-gaapOperatingLeaseLiability" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapOperatingLeaseLiability" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaapStockholdersEquity" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaapPreferredStockValue" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapPreferredStockValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaapCommonStockValue" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapCommonStockValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaapAdditionalPaidInCapital" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapAdditionalPaidInCapital" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaapRetainedEarningsAccumulatedDeficit" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapRetainedEarningsAccumulatedDeficit" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaapStockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_us-gaapStockholdersEquity" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterest" xlink:label="loc_us-gaapMinorityInterest" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_us-gaapMinorityInterest" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaapLiabilitiesAndStockholdersEquity" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquity" xlink:to="loc_us-gaapLiabilities" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaapCommitmentsAndContingencies" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquity" xlink:to="loc_us-gaapCommitmentsAndContingencies" xlink:type="arc" weight="1" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquity" xlink:to="loc_us-gaapStockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/BalanceSheetsParenthetical" xlink:title="00000003 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/StatementsOfOperations" xlink:title="00000004 - Statement - Condensed Consolidated Statements of Operations (Unaudited)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaapOperatingIncomeLoss" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_UnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" xlink:label="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnInvestments" xlink:label="loc_us-gaapUnrealizedGainLossOnInvestments" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapUnrealizedGainLossOnInvestments" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedInvestmentGainsLosses" xlink:label="loc_us-gaapRealizedInvestmentGainsLosses" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapRealizedInvestmentGainsLosses" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FeeIncome" xlink:label="loc_us-gaapFeeIncome" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapFeeIncome" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_FeeIncomeRelatedParty" xlink:label="loc_MDBHFeeIncomeRelatedParty" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_MDBHFeeIncomeRelatedParty" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingIncome" xlink:label="loc_us-gaapOtherOperatingIncome" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapOtherOperatingIncome" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="loc_us-gaapOperatingCostsAndExpenses" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_CompensationCosts" xlink:label="loc_MDBHCompensationCosts" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_MDBHCompensationCosts" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_OperatingExpenseRelatedParty" xlink:label="loc_MDBHOperatingExpenseRelatedParty" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_MDBHOperatingExpenseRelatedParty" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees" xlink:label="loc_us-gaapProfessionalFees" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_us-gaapProfessionalFees" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommunicationsAndInformationTechnology" xlink:label="loc_us-gaapCommunicationsAndInformationTechnology" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_us-gaapCommunicationsAndInformationTechnology" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_ClearingAndOtherCharges" xlink:label="loc_MDBHClearingAndOtherCharges" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_MDBHClearingAndOtherCharges" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense" xlink:label="loc_us-gaapOtherGeneralAndAdministrativeExpense" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingCostsAndExpenses" xlink:to="loc_us-gaapOtherGeneralAndAdministrativeExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_NetOperatingIncomeLoss" xlink:label="loc_MDBHNetOperatingIncomeLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_MDBHNetOperatingIncomeLoss" xlink:to="loc_us-gaapOperatingIncomeLoss" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_MDBHNetOperatingIncomeLoss" xlink:to="loc_us-gaapOperatingCostsAndExpenses" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_MDBHNetOperatingIncomeLoss" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_MiscellaneousIncome" xlink:label="loc_MDBHMiscellaneousIncome" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_MDBHMiscellaneousIncome" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncome" xlink:label="loc_us-gaapOtherNonoperatingIncome" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_us-gaapOtherNonoperatingIncome" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_LossRelatedToDilutionEvents" xlink:label="loc_MDBHLossRelatedToDilutionEvents" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_MDBHLossRelatedToDilutionEvents" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_UnrealizedGainOnInvestmentSecuritiesNetFromNonlicensedBrokerDealer" xlink:label="loc_MDBHUnrealizedGainOnInvestmentSecuritiesNetFromNonlicensedBrokerDealer" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_MDBHUnrealizedGainOnInvestmentSecuritiesNetFromNonlicensedBrokerDealer" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestment" xlink:label="loc_MDBHIncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestment" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_MDBHIncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestment" xlink:to="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaapIncomeTaxExpenseBenefit" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_MDBHIncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestment" xlink:to="loc_us-gaapIncomeTaxExpenseBenefit" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaapProfitLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapProfitLoss" xlink:to="loc_MDBHIncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestment" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_IncomeLossFromEquityMethodInvestment" xlink:label="loc_MDBHIncomeLossFromEquityMethodInvestment" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapProfitLoss" xlink:to="loc_MDBHIncomeLossFromEquityMethodInvestment" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLoss" xlink:to="loc_us-gaapProfitLoss" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="loc_us-gaapNetIncomeLossAttributableToNoncontrollingInterest" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLoss" xlink:to="loc_us-gaapNetIncomeLossAttributableToNoncontrollingInterest" xlink:type="arc" weight="-1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/StatementsOfChangesInEquity" xlink:title="00000005 - Statement - Condensed Consolidated Statements of Changes in Equity (Unaudited)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/StatementsOfCashFlows" xlink:title="00000006 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaapProfitLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapProfitLoss" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_UnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" xlink:label="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNetFromLicensedBrokerDealer" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnInvestments" xlink:label="loc_us-gaapUnrealizedGainLossOnInvestments" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapUnrealizedGainLossOnInvestments" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_UnrealizedLossOnInvestmentSecuritiesNotHeldByLicensedBrokerDealer" xlink:label="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNotHeldByLicensedBrokerDealer" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHUnrealizedLossOnInvestmentSecuritiesNotHeldByLicensedBrokerDealer" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaapShareBasedCompensation" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapShareBasedCompensation" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaapDepreciationDepletionAndAmortization" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapDepreciationDepletionAndAmortization" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDeferredIncomeTaxes" xlink:label="loc_us-gaapIncreaseDecreaseInDeferredIncomeTaxes" />
      <link:calculationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInDeferredIncomeTaxes" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_ProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDeal" xlink:label="loc_MDBHProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDeal" />
      <link:calculationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDeal" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_ProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDealRelatedParty" xlink:label="loc_MDBHProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDealRelatedParty" />
      <link:calculationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHProceedsFromWarrantsIssuedAsPartOfInvestmentBankingDealRelatedParty" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_StockReceivedInLieuOfCash" xlink:label="loc_MDBHStockReceivedInLieuOfCash" />
      <link:calculationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHStockReceivedInLieuOfCash" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_PortionOfLossFromEquityInvestment" xlink:label="loc_MDBHPortionOfLossFromEquityInvestment" />
      <link:calculationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHPortionOfLossFromEquityInvestment" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="mdbh-20260630.xsd#MDBH_LossRelatedToDilutionEvents" xlink:label="loc_MDBHLossRelatedToDilutionEvents" />
      <link:calculationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_MDBHLossRelatedToDilutionEvents" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:label="loc_us-gaapOperatingLeaseRightOfUseAssetAmortizationExpense" />
      <link:calculationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapOperatingLeaseRightOfUseAssetAmortizationExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="loc_us-gaapIncreaseDecreaseInOperatingLeaseLiability" />
      <link:calculationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInOperatingLeaseLiability" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDueFromRelatedPartiesCurrent" xlink:label="loc_us-gaapIncreaseDecreaseInDueFromRelatedPartiesCurrent" />
      <link:calculationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInDueFromRelatedPartiesCurrent" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaapIncreaseDecreaseInAccountsReceivable" />
      <link:calculationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInAccountsReceivable" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaapIncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" />
      <link:calculationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDepositOtherAssets" xlink:label="loc_us-gaapIncreaseDecreaseInDepositOtherAssets" />
      <link:calculationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInDepositOtherAssets" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherAccountsPayable" xlink:label="loc_us-gaapIncreaseDecreaseInOtherAccountsPayable" />
      <link:calculationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInOtherAccountsPayable" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPayablesToCustomers" xlink:label="loc_us-gaapIncreaseDecreaseInPayablesToCustomers" />
      <link:calculationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInPayablesToCustomers" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDueToRelatedPartiesCurrent" xlink:label="loc_us-gaapIncreaseDecreaseInDueToRelatedPartiesCurrent" />
      <link:calculationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInDueToRelatedPartiesCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="loc_us-gaapIncreaseDecreaseInAccruedIncomeTaxesPayable" />
      <link:calculationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="loc_us-gaapIncreaseDecreaseInAccruedLiabilities" />
      <link:calculationArc order="23" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInAccruedLiabilities" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromProductiveAssets" xlink:label="loc_us-gaapPaymentsForProceedsFromProductiveAssets" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" xlink:to="loc_us-gaapPaymentsForProceedsFromProductiveAssets" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/StatementsOfCashFlowsSupplementalDisclosures" xlink:title="00000007 - Statement - Condensed Consolidated Statements of Cash Flows, Supplemental Disclosures">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations" xlink:label="loc_us-gaapCashAndSecuritiesSegregatedUnderFederalAndOtherRegulations" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="loc_us-gaapCashAndSecuritiesSegregatedUnderFederalAndOtherRegulations" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/OrganizationAndDescriptionOfBusiness" xlink:title="999008 - Disclosure - Organization and Description of Business" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SummaryOfSignificantAccountingPolicies" xlink:title="999009 - Disclosure - Summary of Significant Accounting Policies" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SegmentReporting" xlink:title="999010 - Disclosure - Segment Reporting" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityAndNon-controllingInterests" xlink:title="999011 - Disclosure - Equity and Non-Controlling Interests" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityMethodInvestment" xlink:title="999012 - Disclosure - Equity Method Investment" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/Stock-basedCompensation" xlink:title="999013 - Disclosure - Stock-Based Compensation" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EarningsPerShare" xlink:title="999014 - Disclosure - Earnings Per Share" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/RelatedPartyTransactions" xlink:title="999015 - Disclosure - Related Party Transactions" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/CommitmentsAndContingencies" xlink:title="999016 - Disclosure - Commitments and Contingencies" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EmployeeBenefitPlans" xlink:title="999017 - Disclosure - Employee Benefit Plans" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ExclusiveLicenseAgreementMdbMinnesotaOne" xlink:title="999018 - Disclosure - Exclusive License Agreement (MDB Minnesota One)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/Leases" xlink:title="999019 - Disclosure - Leases" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/IncomeTaxes" xlink:title="999020 - Disclosure - Income Taxes" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SubsequentEvents" xlink:title="999021 - Disclosure - Subsequent Events" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:title="999022 - Disclosure - Summary of Significant Accounting Policies (Policies)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:title="999023 - Disclosure - Summary of Significant Accounting Policies (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SegmentReportingTables" xlink:title="999024 - Disclosure - Segment Reporting (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityAndNon-controllingInterestsTables" xlink:title="999025 - Disclosure - Equity and Non-Controlling Interests (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityMethodInvestmentTables" xlink:title="999026 - Disclosure - Equity Method Investment (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/Stock-basedCompensationTables" xlink:title="999027 - Disclosure - Stock-Based Compensation (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EarningsPerShareTables" xlink:title="999028 - Disclosure - Earnings Per Share (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/LeasesTables" xlink:title="999029 - Disclosure - Leases (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/OrganizationAndDescriptionOfBusinessDetailsNarrative" xlink:title="999030 - Disclosure - Organization and Description of Business (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SummaryOfSignificantAccountingPoliciesDetailsNarrative" xlink:title="999031 - Disclosure - Summary of Significant Accounting Policies (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfInvestmentSecuritiesBrokerDealerDetails" xlink:title="999032 - Disclosure - Schedule of Investment Securities Broker Dealer (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfInvestmentSecuritiesNon-brokerDealerDetails" xlink:title="999033 - Disclosure - Schedule of Investment Securities Non-Broker Dealer (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfFairValueOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" xlink:title="999034 - Disclosure - Schedule of Fair Value of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfReconciliationOfFairValueMeasurementsWithinLevel3OfFairValueHierarchyDetails" xlink:title="999035 - Disclosure - Schedule of Reconciliation of Fair Value Measurements Within Level 3 of Fair Value Hierarchy (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfSignificantUnobservableInputsRelatedToMaterialComponentsOfLevel3WarrantsDetails" xlink:title="999036 - Disclosure - Schedule of Significant Unobservable Inputs Related to Material Components of Level 3 Warrants (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentDetails" xlink:title="999037 - Disclosure - Schedule of Estimated Useful Lives of Property and Equipment (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfPropertyAndEquipmentDetails" xlink:title="999038 - Disclosure - Schedule of Property And Equipment (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaapPropertyPlantAndEquipmentGross" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="loc_us-gaapMachineryAndEquipmentGross" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentGross" xlink:to="loc_us-gaapMachineryAndEquipmentGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FurnitureAndFixturesGross" xlink:label="loc_us-gaapFurnitureAndFixturesGross" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentGross" xlink:to="loc_us-gaapFurnitureAndFixturesGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:label="loc_us-gaapCapitalizedComputerSoftwareGross" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentGross" xlink:to="loc_us-gaapCapitalizedComputerSoftwareGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseholdImprovementsGross" xlink:label="loc_us-gaapLeaseholdImprovementsGross" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentGross" xlink:to="loc_us-gaapLeaseholdImprovementsGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaapPropertyPlantAndEquipmentNet" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentNet" xlink:to="loc_us-gaapPropertyPlantAndEquipmentGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaapAccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapPropertyPlantAndEquipmentNet" xlink:to="loc_us-gaapAccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="arc" weight="-1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfLong-livedAssetsAndTotalAssetsBySegmentDetails" xlink:title="999039 - Disclosure - Schedule of Long-lived Assets and Total Assets by Segment (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfStatementOfOperationBySegmentDetails" xlink:title="999040 - Disclosure - Schedule of Statement of Operation by Segment (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SegmentReportingDetailsNarrative" xlink:title="999041 - Disclosure - Segment Reporting (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfEquityAndNon-controllingInterestsDetails" xlink:title="999042 - Disclosure - Schedule of Equity and Non-Controlling Interests (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityAndNon-controllingInterestsDetailsNarrative" xlink:title="999043 - Disclosure - Equity and Non-Controlling Interests (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfEquityMethodInvestmentDetails" xlink:title="999044 - Disclosure - Schedule of Equity Method Investment (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EquityMethodInvestmentDetailsNarrative" xlink:title="999045 - Disclosure - Equity Method Investment (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfRestrictedStockUnitActivityDetails" xlink:title="999046 - Disclosure - Schedule of Restricted Stock Unit Activity (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfTime-basedStockOptionActivityDetails" xlink:title="999047 - Disclosure - Schedule of Time-Based Stock Option Activity (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfMarket-basedStockOptionActivityDetails" xlink:title="999048 - Disclosure - Schedule of Market-Based Stock Option Activity (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/Stock-basedCompensationDetailsNarrative" xlink:title="999049 - Disclosure - Stock-Based Compensation (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfBasicAndFullyDilutedDetails" xlink:title="999050 - Disclosure - Schedule of Basic and Fully Diluted (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/RelatedPartyTransactionsDetailsNarrative" xlink:title="999051 - Disclosure - Related Party Transactions (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/CommitmentsAndContingenciesDetailsNarrative" xlink:title="999052 - Disclosure - Commitments and Contingencies (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/EmployeeBenefitPlansDetailsNarrative" xlink:title="999053 - Disclosure - Employee Benefit Plans (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ExclusiveLicenseAgreementMdbMinnesotaOneDetailsNarrative" xlink:title="999054 - Disclosure - Exclusive License Agreement (MDB Minnesota One) (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfOperatingLeaseCostDetails" xlink:title="999055 - Disclosure - Schedule of Operating Lease Cost (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/ScheduleOfFuturePaymentsDueUnderOperatingLeaseDetails" xlink:title="999056 - Disclosure - Schedule of Future payments Due Under Operating Lease (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearTwo" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearThree" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearFour" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="loc_us-gaapLesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/LeasesDetailsNarrative" xlink:title="999057 - Disclosure - Leases (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/IncomeTaxesDetailsNarrative" xlink:title="999058 - Disclosure - Income Taxes (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://mdb.com/role/SubsequentEventsDetailsNarrative" xlink:title="999059 - Disclosure - Subsequent Events (Details Narrative)" />
</link:linkbase>
