Free Tool — 2026
Mortgage Stress Test Calculator Canada
Find your maximum purchase price under the OSFI B-20 stress test rules. See your GDS and TDS ratios instantly — and understand exactly what limits your qualification.
Current qualifying rate based on live rate: 6.89%
Your Financial Details
Stress test rate: 6.89% (contract + 2% or 5.25%, whichever is higher)
Maximum Purchase Price
$582,961
Based on $482,961 mortgage + $100,000 down payment
Max Mortgage
$482,961
Before down payment
Stress Test Rate
6.89%
vs contract 4.89%
GDS Ratio Limit
≤ 39%
OSFI limit: 39%
TDS Ratio Limit
≤ 44%
OSFI limit: 44%
What Limits Your Qualification
Your GDS ratio is the binding constraint. Your housing costs (mortgage payment + property tax + heating + 50% condo fees) relative to your gross income are the limiting factor — not your other debts.
To increase your maximum: consider a higher down payment, a longer amortization, or a lower-cost property.
How the Stress Test Calculates Your Ratios
Stress test rate: max(your contract rate + 2.00%, 5.25%) = 6.89%
GDS formula: (monthly mortgage payment + property tax ÷ 12 + heating + 50% condo fees) ÷ gross monthly income ≤ 39%
TDS formula: (all GDS costs + all monthly debt payments) ÷ gross monthly income ≤ 44%
Based on OSFI Guideline B-20. Assumes 25-year amortization for qualification purposes.
What Is the Mortgage Stress Test?
Since January 2018, the Office of the Superintendent of Financial Institutions (OSFI) has required all federally regulated lenders to test mortgage applicants at a qualifying rate higher than their actual contract rate. The rule — known as Guideline B-20 — applies regardless of down payment size.
The stress test does not change your actual mortgage rate. You still pay your contract rate. The qualifying rate is used only to determine whether you can afford the mortgage if rates increase — ensuring borrowers are not stretched to their absolute limit at the current rate environment.
The qualifying rate is the greater of your contract rate plus 2.00%, or a floor rate of 5.25%. As of 2026, this floor has not changed since OSFI set it in June 2021.
Why the Stress Test Exists
The stress test was introduced after OSFI observed that many Canadians were taking on mortgages at the very limit of what they could afford at then-current rates. If rates rose modestly — as they did dramatically in 2022–2023 — a significant portion of borrowers would face payment shock at renewal.
+2.00%
Buffer above contract rate
Built-in protection for rate increases
5.25%
Minimum qualifying floor
Applies even when rates are very low
39% / 44%
GDS / TDS ratio limits
Maximum housing cost ratios
GDS Ratio Explained
The Gross Debt Service ratio (GDS) measures the percentage of your gross (pre-tax) monthly income that goes toward housing costs. Lenders must keep your GDS at or below 39% to approve your mortgage.
GDS Formula:
(Monthly Mortgage Payment + Property Tax / 12 + Heating + 50% Condo Fees)
Gross Monthly Income
= GDS Ratio (must be ≤ 39%)
Note: the monthly mortgage payment in the GDS calculation uses the stress test rate, not your actual contract rate. This is what limits most first-time buyers.
TDS Ratio Explained
The Total Debt Service ratio (TDS) adds all your non-housing monthly debt payments to the GDS housing costs. The combined amount must not exceed 44% of gross monthly income.
TDS Formula:
(All GDS Housing Costs + Car Payments + Student Loans + Credit Card Minimums)
Gross Monthly Income
= TDS Ratio (must be ≤ 44%)
The 5% gap between the GDS and TDS limits (39% vs 44%) is the maximum debt service your non-housing debts can consume. If you have $800/month in car and student loan payments, that effectively reduces your maximum mortgage by a significant amount.
How to Improve Your Stress Test Result
Add a co-borrower
Adding a spouse, partner, or parent as a co-borrower is the single most effective strategy. Their income is added to yours, directly increasing the maximum mortgage.
Pay down non-housing debts first
Eliminating a $600/month car payment before applying can increase your maximum mortgage by $70,000–$100,000 depending on your income. If you can clear debts before applying, do it.
Increase your down payment
A larger down payment reduces the required mortgage. It also may allow you to avoid CMHC insurance and qualify for a 30-year amortization (if you are putting 20%+ down), which lowers the qualifying monthly payment.
Work with a mortgage broker
Brokers have access to lenders that calculate income more generously — including self-employment income, rental income, bonuses, and overtime. A bank may qualify you on base salary only; a broker may be able to use your full income picture.
Frequently Asked Questions
Free — No Obligation
Maximize Your Qualification
A broker can find lenders that qualify more of your income and get you a lower rate — both of which increase your maximum mortgage.