Free calculator · Qualifying & Pre-Approval
Mortgage Affordability Calculator
Estimate the maximum home price and mortgage you may qualify for using Canadian gross debt service (GDS) and total debt service (TDS) ratios.
Estimate how much you may qualify to borrow
This tool applies the federal Gross Debt Service (GDS) and Total Debt Service (TDS) limits and the mortgage stress test to estimate the largest mortgage and home price your income may support. Enter your own figures — nothing is assumed except the qualifying-rate floor, which you can change.
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Estimates only. This is not a quote, pre-approval, or approval. Lenders apply their own credit, income, and property rules, and the stress-test floor changes over time.
How this is calculated
Your gross income is converted to a monthly figure. Housing costs are the mortgage principal and interest, property taxes, heating, and 50% of condo fees. Under the GDS limit, housing costs may not exceed 39% of gross monthly income; under the TDS limit, housing costs plus all other debt payments may not exceed 44%. The tool finds the smaller payment that satisfies both limits, then solves backwards from that payment at the stress-test qualifying rate — the higher of your contract rate plus two percentage points, or the qualifying-rate floor you entered — to find the maximum mortgage. Adding your available down payment gives the estimated maximum home price.
GDS and TDS explained
The Gross Debt Service ratio measures how much of your income goes to housing alone. The Total Debt Service ratio adds every other recurring debt payment. A lender compares both against its limits and uses whichever is more restrictive. Carrying high credit-card or loan payments lowers how much mortgage you can support even if your income is strong, because those payments consume room under the 44% TDS ceiling.
How the stress test changes what you can borrow
Since the federal stress test was introduced, most federally regulated lenders must confirm you can still afford the payments if rates rise. They do this by qualifying you at the higher of your contract rate plus two percentage points or the published floor, then calculating your debt ratios at that rate. The result is that you may qualify for less than the payment you will actually make today. The floor is set periodically, so confirm the current figure with OSFI or your lender.
Why a lender's number may differ
- Lenders may use a different heating allowance, property-tax estimate, or condo-fee treatment.
- Your credit score, employment history, and down-payment source affect approval and pricing.
- Insured mortgages have maximum purchase-price and amortization limits.
- This estimate ignores mortgage default insurance premiums, which are added to the loan on high-ratio purchases.