How to Calculate Your Canadian Mortgage Payment (And What the Banks Don't Tell You)
Learn how Canadian mortgage payments are calculated, why semi-annual compounding matters, and what your true monthly housing cost really looks like.
How to Calculate Your Canadian Mortgage Payment (And What the Banks Don't Tell You)
When a lender quotes you a mortgage rate, that number doesn't mean the same thing in Canada as it does in the United States. Canadian mortgages use semi-annual compounding — a legal requirement under the Interest Act — which means your effective monthly rate is slightly lower than simply dividing the posted rate by 12. The difference is small but it affects every payment you'll ever make.
What Goes Into a Mortgage Payment
Your monthly mortgage payment has two components: principal (reducing your loan balance) and interest (the lender's cost of lending). In the early years of a mortgage, the vast majority of each payment is interest. This shifts gradually over the amortization period.
Beyond principal and interest, lenders and insurers want to see your total housing costs — often called PITH:
- Principal and interest (your mortgage payment)
- Insurance (home/fire insurance)
- Taxes (property tax)
- Heating (monthly utility estimate)
If you're in a condo, strata/condo fees are also included at 50% for qualification purposes.
The Stress Test and Your Payment
Since 2018, federally regulated lenders must qualify you at the higher of:
- Your contract rate + 2%, or
- 5.25% (the OSFI minimum qualifying rate)
This means your qualifying payment is higher than your actual payment. A mortgage you can afford today may not pass the stress test if rates are already high.
Amortization: 25 vs. 30 Years
The maximum amortization for insured mortgages (less than 20% down) is 25 years. For conventional mortgages (20%+ down), lenders can offer up to 30 years, though not all do.
A longer amortization lowers your monthly payment but significantly increases total interest paid. A $500,000 mortgage at 5% over 25 years costs about $73,000 more in interest than the same mortgage over 20 years.
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Official Resources
- Bank of Canada — Mortgage Rate Tool — current benchmark and posted rates
- OSFI — Residential Mortgage Underwriting Practices — stress test rules (B-20 guideline)
- FCAC — Mortgage Calculator — Financial Consumer Agency of Canada official tool
- Canada Interest Act (RSC 1985, c I-15) — the law requiring semi-annual compounding on Canadian mortgages
- CMHC — Homebuying Step by Step — CMHC consumer mortgage resources