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Canadian Mortgage Affordability Calculator

Estimate your max purchase price using GDS, TDS, and the OSFI stress test. Includes CMHC down-payment tiers and insurance estimate.

Reviewed by Canadian Money Help Editorial Updated May 6, 2026 Source CMHC + OSFI 2026

Quick answer: Affordability in Canada is capped by GDS (≤ 39% of gross monthly income on housing) and TDS (≤ 44% on housing + all other debts), measured at the OSFI stress-tested rate — the higher of your contract rate plus 2 percentage points or 5.25%.

What this means: The stress test is the binding constraint for most buyers. Property tax, heating, and 50% of any condo fees count in GDS. Down payment of less than 20% triggers CMHC insurance, which is added to the mortgage principal.

What to do next: Enter your income, debts, and down payment below.

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How the calculator works

This calculator estimates the maximum mortgage and purchase price you qualify for under the standard Canadian lender framework: GDS ≤ 39% and TDS ≤ 44% at the stress-tested qualifying rate.

  • The qualifying rate is your contract rate plus 2 percentage points, or 5.25%, whichever is higher (OSFI B-20).
  • Property tax (annual / 12), heating cost, and 50% of monthly condo fees count toward both ratios.
  • Other monthly debt payments add to TDS but not GDS.
  • Mortgage payments use semi-annual Canadian compounding (the standard convention).

What the calculator does not model

  • Lender-specific overlays. Some lenders apply tighter ratios (38% / 42%) or surcharge investment properties.
  • Qualifying income adjustments. Bonus, commission, and self-employment income are typically averaged or discounted by lenders. The calc assumes the income you enter is the qualifying amount.
  • Provincial land transfer tax. Use the land transfer tax calculator for closing-cost planning.
  • Closing costs in general. Allow 1.5%-4% on top of the purchase price for legal, title insurance, inspections, and adjustments.

Methodology and sources

GDS / TDS limits from CMHC’s GDS/TDS calculation guidance. Stress test from OSFI Guideline B-20. CMHC insurance premium tiers from CMHC’s 2024 schedule. This site is lender-independent: no affiliate relationships with any Canadian mortgage lender, broker, or insurer.

Frequently asked questions

What is the maximum mortgage I can afford in Canada?
Capped by GDS ≤ 39% and TDS ≤ 44% of gross monthly income, measured at the OSFI stress-tested rate (your contract rate + 2 percentage points, or 5.25%, whichever is higher).
What is GDS in a Canadian mortgage?
Gross Debt Service ratio: principal + interest + property tax + heat + 50% of condo fees, divided by gross monthly income. Most lenders cap GDS at 39%.
What is TDS in a Canadian mortgage?
Total Debt Service ratio: GDS expenses plus all other monthly debt payments (car loans, credit cards, lines of credit, student loans), divided by gross monthly income. Most lenders cap TDS at 44%.
What is the mortgage stress test?
OSFI B-20 requires lenders to qualify borrowers at the higher of contract rate + 2 percentage points or 5.25%. Applies to all federally regulated lenders for new purchases, refinances, and lender switches. Renewals with the same lender are exempt since 2024.
What's the minimum down payment in Canada?
5% on the first $500,000, 10% on the $500,000-$1,500,000 portion, and 20% on properties over $1.5 million (uninsured). The $1.5M insurable cap took effect December 15, 2024.
When does CMHC insurance apply?
When the down payment is less than 20% and the property is $1.5M or less. The premium (0.6%-4.0% of mortgage amount, by loan-to-value tier) is added to the mortgage principal.

Methodology

Maximum monthly housing budget is the lesser of (39% of gross monthly income minus monthly property tax minus monthly heat) and (44% of gross monthly income minus monthly property tax minus monthly heat minus other monthly debt). The maximum mortgage payment is this budget. The maximum mortgage amount inverts the Canadian mortgage formula at the qualifying rate (the greater of the contract rate plus two percentage points and 5.25%) with semi-annual compounding. Maximum purchase price is the maximum mortgage plus the down payment, floor-adjusted for the 5%, 5+10%, and 20% minimum down payment rules. Actual monthly payment at the contract rate is computed with the same formula at the contract rate. CMHC, Sagen, and Canada Guaranty premium tables are applied to insured mortgages at the 2024 rate schedule.