Canada · educational scenario

Canadian GDS, TDS and CMHC calculator

Estimate Gross Debt Service, Total Debt Service and a high-ratio CMHC premium for a Canadian purchase scenario. This is not a lender approval, insurer decision or stress-test result for a named borrower.

Insured-mortgage planning limits
The default 39% GDS and 44% TDS markers are the insured-mortgage limits described in OSFI B-20. Uninsured lender overlays can differ.

Your scenario

Income, purchase and housing costs

Live estimate

Annual gross income

Household income before taxMonthly other debts

Loans, cards and other recurring debtPurchase price

Contract price used for LTVDown payment

Cash applied to the purchase priceContract interest rate

Quoted annual rate, compounded semi-annuallyAmortization

years

Beyond 25 years adds the published 0.20% CMHC surchargeAnnual property tax

Enter a current local estimateMonthly heating

Included in GDS as a housing costMonthly condo / strata fees

GDS uses 50% of this amountAdd the CMHC premium to the loan amount

GDS uses the qualifying rate of the greater of the contract rate plus 2 percentage points or 5.25%. Provincial sales tax on premiums, energy-efficient refunds, non-traditional down payments and insurer overlays are not modelled.

How it works

GDS, TDS and CMHC stay separate from a lender quote.

Gross Debt Service is qualifying-rate principal and interest plus property tax, heating and half of condo fees, divided by gross monthly income. Total Debt Service adds other debt payments. The 39% and 44% markers are the insured-mortgage limits described by OSFI, not a promise that an uninsured lender will use the same caps.

The premium uses the published CMHC homeowner schedule on the total loan amount. It does not price Sagen, Canada Guaranty, provincial sales tax, portability credits or eligibility for a 30-year insured amortization.

Sources: CMHC mortgage loan insurance premium schedule for homeowner loans · reviewed 2026-09-16. OSFI Guideline B-20 residential mortgage underwriting practices and procedures · reviewed 2026-09-16.

Read the calculation methodology (English).