Canadian Mortgage Payment Calculator
Canadian mortgages compound semi-annually, not monthly. A 5% mortgage in Canada is mathematically a different beast than a 5% mortgage in the US — the effective monthly rate is slightly lower. Most online calculators get this wrong. This one gets it right: every payment is computed against the periodic rate derived from semi-annual compounding per the Interest Act.
Most online “Canadian” mortgage calculators silently use the US monthly-compounding formula and quote a number $20-$60/month higher than the lender actually charges.
Calculate
- Periodic payment (Monthly)
- $4,883.13
- Annual payment
- $58,598
- Total interest over 25-year amortization
- $664,940
- Total cost of mortgage (principal + interest)
- $1,464,940
- Year-5 snapshot — principal remaining
- $713,500
- Year-5 snapshot — interest paid through year 5
- $206,488
Estimate only. Your lender will produce the binding amortization schedule on commitment day. Numbers reflect an idealized constant-rate amortization; renewal at year 5 will reset the periodic rate to whatever the market is doing then.
Reproduce this number4 steps
| Step | Amount |
|---|---|
| Periodic rate (semi-annual compounding): (1 + 5.5/200)^(2/12) − 1 = 0.453168% (osfi.b20.stress_test) | $4,883.13 |
| Monthly payment over 25-year amortization (300 payments) | $4,883.13 |
| Annual payment (periodic × payments-per-year) | $58,597.58 |
| Total interest paid over 25-year amortization | $664,939.56 |
| Total | $4,883.13 |
Computed from the BC Real Estate Codex · CC BY 4.0
Why semi-annual compounding matters
The Canadian Interest Act (RSC 1985, c. I-15, §6) requires that the interest rate quoted on a fixed-rate mortgage be expressed at a maximum compounding frequency of semi-annually, not in advance. Lenders comply by computing the periodic (monthly / bi-weekly) rate as the equivalent rate that, compounded semi-annually, would yield the quoted nominal rate.
Practically: a 5.5% Canadian mortgage has a periodic monthly rate of approximately 0.4531%, not 0.4583% as the US monthly-in-advance convention would imply. On an $800,000 mortgage over 25 years, that 0.5 basis-point difference compounds to roughly $30 per month and over $9,000 across the amortization. A US-style calculator quoting Canadian rates produces a meaningfully wrong answer.
Variable-rate mortgages are typically compounded monthly (since the rate floats), but the principal-protection mechanism in the Interest Act still applies. This calculator assumes fixed-rate semi-annual compounding by default, which is the most common BC scenario.
OSFI stress test: this is what you actually qualify at
The contract rate above is what you’ll PAY. The OSFI stress test (OSFI Guideline B-20 mortgage stress test) qualifies you at the GREATER of contract rate + 2 percentage points or 5.25%. To see what mortgage size that translates to under your income, use the affordability calculator.
Source: /codex#osfi.b20.stress_test
Related
Verified sources (1)Click to expand
Every claim on this page is sourced to a primary government, regulator, or industry-association URL. We re-verify quarterly; the verification dates below show when each source was last confirmed against the live government page.
- OSFIretrieved 2026-05-08Guideline B-20: Residential Mortgage Underwriting Practices and Procedureshttps://www.osfi-bsif.gc.ca/Eng/fi-if/rg-ro/gdn-ort/gl-ld/Pages/b20.aspx
osfi.b20.stress_test · v1View in Codex →Verified sources (1)Click to expand
Every claim on this page is sourced to a primary government, regulator, or industry-association URL. We re-verify quarterly; the verification dates below show when each source was last confirmed against the live government page.
- Government of Canadaretrieved 2026-05-08· published 2024-09-16Government Announces Boldest Mortgage Reforms in Decadeshttps://www.canada.ca/en/department-finance/news/2024/09/government-announces-boldest-mortgage-reforms-in-decades-to-unlock-homeownership-for-more-canadians.html
cmhc.amortization_30yr_eligibility · v1View in Codex →