Mortgage Stress Test Calculator

What the Mortgage Stress Test Calculator does

The federal stress test is the single most misunderstood rule in Canadian mortgage lending: you qualify at one rate and pay a different, lower one. This calculator runs the actual test — computing your qualifying rate, the payment it produces, and whether your income and debts clear the GDS and TDS limits at that higher payment — and puts your real payment right beside it, so the gap is visible rather than abstract.

It also answers the exemption question that trips up almost every renewing borrower: whether switching lenders, staying put, refinancing or buying changes whether the test applies to you at all.

• Your qualifying rate, and the payment it produces on your mortgage amount
• A clear pass or fail against the 39% GDS and 44% TDS limits
• Your actual payment shown side by side with your qualifying payment
• If you fail: the maximum price that would pass, and the income needed at your current price
• Whether your transaction type may be exempt from re-testing, and the credit union alternative

The variables that move the answer — and how lenders treat them

The result is driven by a small set of inputs, and each interacts with the test differently than it interacts with your actual payment.

• Contract rate — sets your actual payment, but the qualifying rate is derived from it by adding 2 percentage points. At today’s typical rates the 5.25% benchmark rarely binds; the add-on almost always does.
• Down payment — decides whether the mortgage is insured, which changes the mortgage amount through the capitalised premium, but does not exempt anyone from the test. Every mortgage in Canada, insured or not, is stress tested.
• Amortization — a longer amortization lowers the qualifying payment along with the actual one, which is one of the few levers directly within a borrower’s control when a file is failing.
• Transaction type — this is where lenders diverge from the general rule. A straight switch of an existing, uninsured mortgage to a new federally regulated lender at renewal may be exempt from re-testing, and staying with your existing lender has historically never required requalification. A purchase or a refinance is always tested.
• Lender type — provincially regulated credit unions are generally not bound by the federal OSFI B-20 stress test, though they may apply their own standards. This is a genuine structural reason a borrower can fail at a bank and pass at a credit union.

How the stress test is actually calculated

The qualifying rate is the greater of your contract rate plus 2.00 percentage points, or a fixed benchmark floor — currently 5.25%. That rate, not your contract rate, is used to compute the payment that feeds your GDS and TDS ratios.

The qualifying payment is calculated the same way as any Canadian mortgage payment, using the periodic rate formula with semi-annual compounding, but substituting the qualifying rate: i = (1 + rate ÷ 2)^(2 ÷ 12) − 1, then payment = P × i ÷ (1 − (1 + i)^−N). That qualifying payment is then run through the same GDS and TDS calculation used everywhere else on this site.

When a file fails, the useful next question is what would pass. The maximum passing price is solved by testing candidate prices against the ratio limits at the qualifying rate, holding the down payment fixed. The income needed at the current price is solved directly from the ratio formulas, taking the higher of the income required to satisfy GDS alone and the income required to satisfy TDS alongside existing debts.

• Qualifying rate = MAX(contract rate + 2.00%, 5.25%)
• Qualifying payment: the standard Canadian payment formula, using the qualifying rate
• Pass/fail: qualifying payment run through GDS ≤ 39% and TDS ≤ 44%
• If failing: max price solved by bisection; income needed solved directly from the limits

How lenders use these numbers to qualify you

Every output here is the exact figure an underwriter checks. This is not an approximation of the stress test — it is the stress test.

• Qualifying rate — the number lenders substitute for your contract rate before running any ratio. Disclosed on every rate quote, rarely explained.
• Pass/fail — the binary gate. A fail means the file does not clear as structured, regardless of how attractive the contract rate is.
• The gap between actual and qualifying payment — this exists specifically as a buffer against future rate increases. Lenders are testing whether you could absorb higher rates without becoming unable to pay.
• Maximum passing price — tells you exactly how much price flexibility closes the gap, which is usually more useful than the pass/fail badge alone.
• Exemption flag — matters most at renewal, where a straight switch of an uninsured mortgage may not require the test at all, changing which lenders are realistically available.

Using your results well

If you are failing, run it again with a longer amortization and again with a lower target price to see which lever closes the gap faster for your numbers. The maximum-price and income-needed figures are calculated directly from your inputs, so they reflect your actual situation rather than a rule of thumb.

What this calculator does not do is check every lender’s specific overlay or confirm exemption eligibility for your exact circumstances. Exemption rules have changed before, differ by lender, and are worth confirming directly rather than assuming from a general description. It also cannot tell you whether a particular credit union’s own standards would let you pass where a bank would not — that comparison is exactly what a broker is positioned to run.

• If failing, compare a longer amortization against a lower target price to see which closes the gap faster
• Check the exemption flag carefully at renewal — it can change which lenders are in play
• Ask specifically about credit unions if you are close to the line
• Treat the maximum-price figure as a ceiling to shop under, not a target to spend up to
• Confirm exemption and qualifying-rule details directly — this area changes