Canada Affordability Calculator

How this Canada affordability calculator works

This calculator estimates mortgage affordability using the debt service approach used in Canadian mortgage underwriting. It applies a 39% Gross Debt Service ratio and a 44% Total Debt Service ratio as the standard reference limits. It also applies the current mortgage stress test rate, which is the greater of your contract rate plus 2 percentage points or 5.25%.

For a home price estimate, the calculator searches for the highest price that fits the debt service limits and the federal minimum down payment rules. If the mortgage would be insured, it adds the applicable CMHC insurance premium to the mortgage before calculating the qualifying payment.

Formula and calculation method

The mortgage payment uses the Canadian convention for a nominal annual mortgage rate compounded twice per year and converted to an equivalent monthly rate. The calculator then uses the selected amortization period to determine the monthly principal and interest payment.

Down payment and mortgage insurance rules used

For an owner occupied 1 or 2 unit home, the calculator uses the federal minimum down payment of 5% on the first $500,000 and 10% on the portion above $500,000 when the purchase price is below $1.5 million. At $1.5 million or more, it requires at least 20% down.

When the loan to value ratio is above 80%, the calculator adds a CMHC purchase insurance premium. For a 25 year amortization it uses the standard CMHC purchase premium schedule. For an eligible 30 year insured mortgage, it uses CMHC Home Start premium rates.

Provincial sales tax on mortgage insurance premiums, where applicable, is not included. CMHC notes that Ontario, Quebec and Saskatchewan apply provincial sales tax to the insurance premium, and that tax cannot be added to the mortgage.

What the result does not include

• Credit score, income verification, employment history, property appraisal, lender specific policies, and other underwriting checks.
• Land transfer taxes, legal fees, home inspection costs, adjustments, moving costs, or other closing expenses.
• Home insurance, maintenance, repairs, utilities other than the heating amount you enter, and personal living expenses.
• Special treatment of rental income, self employed income, child support, alimony, secured credit lines, or other cases that may require lender specific calculations.

CMHC states that closing costs can be about 1.5% to 4% of the purchase price. Keep money for those costs separate from the down payment amount you enter.

Why another calculator may give a different result

Different calculators may use different debt service limits, property tax or heating assumptions, mortgage insurance treatment, interest compounding, rounding, or lender policies. Uninsured mortgages can also be assessed under lender specific underwriting rules, so the 39% GDS and 44% TDS limits used here are a consistent reference rather than a guarantee.

Sources and methodology

• CMHC Purchase for debt service thresholds, insured purchase eligibility, minimum equity, and standard insurance premiums.
• CMHC guidance on calculating GDS and TDS for treatment of property taxes, heating costs, condo fees, and other debts.
• OSFI minimum qualifying rate for the current uninsured mortgage stress test.
• Financial Consumer Agency of Canada down payment guidance for the federal minimum down payment schedule.
• CMHC Home Start for 30 year insured mortgage eligibility and premium rates.
• Financial Consumer Agency of Canada fixed mortgage disclosure example for the Canadian fixed mortgage convention of interest compounded twice per year and charged monthly.

Methodology last reviewed: September 24, 2026.