GDS and TDS: the debt ratios lenders use
Two ratios decide how much a Canadian lender will lend you: how much of your income goes to housing, and how much goes to all your debts.
Figures checked September 24, 2026Gross debt service (GDS)
GDS is the mortgage payment, property tax, heating and half of any condo fees, divided by your gross monthly income. Insured mortgages allow up to 39% when at least one borrower has a credit score of 680 or more; CMHC's standard is 35%.
Total debt service (TDS)
TDS adds every other debt payment to the GDS costs: car loans and leases, student loans, support payments, lines of credit and credit cards. The insured limit is 44% (42% under CMHC's standard).
Credit cards and unsecured lines count at 3% of the balance each month, whatever you actually pay.
Which payment is used
The mortgage payment in both ratios is calculated at the stress-test rate, not your actual rate. That's why the stress test and the ratios together set how much you can borrow.
Improving your ratios
Paying off a car loan or a card balance before you apply can raise what you can borrow more than a bigger down payment would. A longer amortization lowers the payment too. A broker can model the options against lenders' actual rules.
More guides
General information about Canadian mortgages, not financial, legal or tax advice. Lenders and insurers apply their own criteria, and rules change; confirm the details with a licensed mortgage professional before you act.