How the mortgage stress test calculator works
The live tool stays on the stress test calculator. This page is the 2026 rule write-up behind the MQR math.
How the Stress Test Works in 2026
The Canadian mortgage stress test is an OSFI rule (Guideline B-20) that has been the binding qualifying constraint for most Canadian borrowers since 2018. It exists to ensure new borrowers can absorb a meaningful rate increase without payment-shock distress at renewal. The qualifying rate — the Minimum Qualifying Rate, or MQR — is the greater of 5.25% or your contract rate plus 2 percentage points.
Federally regulated lenders apply the MQR to two ratios. GDS (Gross Debt Service) sums your principal and interest at the MQR, your property taxes, and your heating costs, and caps the total at 39% of gross household income. TDS (Total Debt Service) adds your other monthly debt payments (car loans, credit cards, student loans) and caps the combined total at 44% of gross income. Whichever ratio binds first sets your maximum qualifying mortgage.
As of November 21, 2024, OSFI removed the MQR requirement for uninsured straight-switch renewals — borrowers moving an existing mortgage to a new lender at renewal without changing the loan amount, amortization, or payment schedule no longer need to re-qualify at the stress-test rate. Insured mortgages have not required the test on straight switches for years. The stress test still applies to new purchases, refinances, equity take-outs, and any renewal where loan terms change.