UNDERSTAND YOUR MORTGAGE
Mortgage affordability in Québec: what actually limits borrowing?
A mortgage payment estimate is not a borrowing-capacity assessment. Lenders also consider verified income, existing debts, housing expenses and qualification at the stress-test rate.
Estimate how much you could borrow
Edit this example to estimate a mortgage loan amount from GDS and TDS limits—not the purchase price of a home. No data is sent.
Main constraint: —. Example includes $3,600/year in property taxes and $150/month for heat, adjustable above. Based on 39% GDS and 44% TDS. Does not include down payment, mortgage insurance, credit assessment or lender-specific requirements. This is not a mortgage preapproval.
Two separate ratios: GDS and TDS
The gross debt service ratio (GDS) compares housing costs to gross household income. Housing costs may include the mortgage payment at the qualifying rate, property taxes, heating and 50% of eligible condo fees. The total debt service ratio (TDS) also includes other debt payments, including car loans and credit obligations.
Typical CMHC ratio limits are 39% GDS and 44% TDS. Actual underwriting depends on the lender, product and applicant.
Example: $100,000 household gross income
Assume a hypothetical $100,000 annual gross household income and $650 per month in other debts:
| Calculation | Amount |
|---|---|
| 39% of annual income divided by 12 (GDS) | $3,250.00/month |
| 44% of annual income divided by 12 (TDS) | $3,666.67/month |
| TDS minus $650 of other monthly debt | $3,016.67/month |
| Indicative housing-cost ceiling | $3,016.67/month |
This amount must still cover the mortgage payment at the qualifying rate, property taxes, heating and the applicable share of condo fees. It is not an allowable mortgage payment or a preapproval.
The mortgage stress test
Federally regulated banks generally use the higher of 5.25% or the offered mortgage rate plus two percentage points. An illustrative 4.50% rate therefore leads to a 6.50% qualifying rate. See the mortgage stress-test guide for the difference.
Why equal incomes can produce different results
Car loans, credit history, down payment, type of income, condo fees, other obligations and lender underwriting rules can all change the eligible amount. A specific property must also satisfy lending and valuation conditions.
The free mortgage calculator serves a different purpose: it projects the payments on a defined mortgage amount.
What to prepare for a professional review
Verified household income, monthly debts, available down payment, target price, expected property tax, heating charges and condo fees if applicable. A mortgage broker can then review the options that actually apply to the file.
Official sources and limitations
Data and rules checked November 4, 2026. Illustrative figures only; lender terms and eligibility are not guaranteed.