Mortgage Affordability & Stress Test

Your lender runs these exact numbers before saying yes. Find out where you stand, and what rate they will actually test you at.

You will need

  • Gross annual household income
  • Monthly debt payments (car, student loans, etc.)
  • Target home price and down payment
  • Estimated property tax and heating costs

You will know

  • Your GDS and TDS ratios vs lender limits
  • Whether you pass the stress test
  • Maximum home price you qualify for
  • Exactly what rate you will be tested at
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Estimated Max Purchase Price

$673,726

With $150,000 down · qualifying at 5.89% · limited by GDS ratio

Max Monthly Payment

$3,316.67

Max Mortgage Amount

$523.7K

How affordability is calculated in Canada

Canadian lenders use two standardized debt ratios — GDS and TDS — both calculated at the stress test rate rather than your actual rate. The stress test rate is the greater of your contract rate + 2% or 5.25%. This ensures you can handle higher payments if rates rise at renewal.

GDS (Gross Debt Service) covers housing costs only: principal and interest, property taxes, heating, and 50% of condo fees if applicable. The maximum is 39% of gross income.

TDS (Total Debt Service) adds all other debt obligations — car loans, student loans, credit card minimums, lines of credit — to your GDS. The maximum is 44% of gross income.

Your maximum purchase price is wherever one of those constraints binds first. Usually TDS is the binding constraint for buyers with significant debt. For buyers with minimal non-mortgage debt, GDS binds. Reducing your debts before applying is often more effective than saving more for a down payment.

What changed in December 2024

Effective December 15, 2024, the federal government made the most significant affordability changes in a decade. Three things changed simultaneously:

Insured limit

Was: $1,000,000

Now: $1,500,000

Buyers up to $1.5M can now use less than 20% down

GDS limit

Was: 32%

Now: 39%

Housing cost ratio increased — more qualifying power

30-year amortization

Was: Not available insured

Now: Available for first-time buyers

Lower monthly payments, more qualifying room

GDS and TDS limits at a glance

RatioWhat it includesMaximum
GDSMortgage P&I + property tax + heating + 50% condo fees39%
TDSGDS + all other debt payments (car, student, credit)44%

Both ratios are calculated at the stress test rate (contract rate + 2%, minimum 5.25%), not your actual rate.

Frequently asked questions

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