Mortgage Stress Test Calculator

How the stress test works

Since 2018, every mortgage from a federally regulated lender must be qualified at the higher of your contract rate + 2% or 5.25%. You pay the contract rate; you're approved at the stress rate. At a 4.5% contract rate, you must prove you could carry payments at 6.5% — that's the buffer Ottawa insists on in case rates rise before you renew.

The two ratio limits

• GDS — 39%. Mortgage payment (at the stress rate) + property tax + heat + half of condo fees must be under 39% of gross monthly income.
• TDS — 44%. Everything in GDS plus car payments, credit card minimums, student loans, and lines of credit must be under 44%.

Your approval is capped by whichever limit you hit first — this calculator shows both and names the binding one. With clean finances, GDS binds; with a car payment, TDS usually binds first.

Canadian compounding, again

Like our mortgage calculator, the payment-to-principal conversion uses semi-annual compounding as required by Canadian law: the monthly rate is (1 + rate/2)^1/6 − 1. US calculators quietly overstate the payment and understate your qualifying amount.

What moves the needle

• Kill other debt. Each $400/month of debt payments costs roughly $60,000–$70,000 of maximum mortgage under TDS — the highest-leverage move most buyers have.
• Longer amortization. 30 years instead of 25 lowers the tested payment about 8% and raises the cap accordingly (available for uninsured mortgages and for insured first-time buyers of new builds).
• Lower contract rate. A better rate lowers the stress rate too — the qualifying benefit is roughly double the payment benefit.
• Bigger down payment. Adds directly to the maximum price, and crossing 20% avoids CMHC insurance premiums.

What this calculator doesn't include

CMHC insurance premiums (which add 2.8–4.0% to the mortgage when down payments are under 20%), condo fees, lender-specific flexibility above 39/44 for strong files, and credit-score effects on which rates you're offered. Use the output as a strong estimate of your ceiling, then confirm with a real pre-approval — our pre-approval guide walks through that process.