A Canadian mortgage payment is not simply the loan amount times the interest rate. Because Canadian lenders compound interest semi-annually, not monthly, the effective monthly rate is slightly lower than one-twelfth of the contract rate — and that small difference is why a Canadian payment at 4.34% is a few dollars cheaper than the same loan calculated the American way.
The payment formula, step by step
Canadian fixed-rate mortgages compound twice a year. To find the equivalent monthly rate, lenders first convert the contract rate to its semi-annual equivalent and then split it into months:
So at a 4.34% contract rate, the monthly rate is (1 + 0.0434 ÷ 2)1/6 − 1 ≈ 0.3584%, not the 0.3617% you would get dividing by 12. Over 25 years (300 payments) on $400,000, that produces a payment of about $2,178.45 per month. Small inputs, big totals: the same loan repays roughly $253,536 in interest over the amortization.
Worked examples at 2026 rates
Rate context for early October 2026: money.ca listed the lowest advertised 5-year fixed at 3.91% on October 4; Ratehub showed a best-market high-ratio 5-year fixed near 4.34% and a best 5-year variable near 3.40% on October 1; big-bank posted 5-year fixed rates ran roughly 4.59% to 4.99%; and the Bank of Canada's overnight rate stood at 2.25%, with big-bank prime at 4.45%. The table uses 4.34% as a representative competitive fixed rate.
| Mortgage amount | 25-year amortization | 30-year amortization |
|---|---|---|
| $400,000 | $2,178.45 | $1,979.78 |
| $500,000 | $2,723.07 | $2,474.73 |
| $600,000 | $3,267.68 | $2,969.67 |
Payments assume Canadian semi-annual compounding and a 4.34% contract rate held for the full amortization. In reality your rate resets at each renewal, so actual totals will differ.
Why this matters more than the rate alone: at 4.34% over 25 years, a $400,000 mortgage carries about $253,536 of lifetime interest — roughly 63% of the original loan. The payment formula is exact; the inputs are what move the total.
Amortization: the biggest lever you control
Stretching the amortization lowers the payment and raises the qualifying room, but it also keeps the balance high for longer, so more interest accrues. On a $400,000 mortgage at 4.34%:
- 25 years: $2,178.45/month, about $253,536 in lifetime interest.
- 30 years: $1,979.78/month (about $199 less), but roughly $312,722 in lifetime interest — about $59,000 more.
- The rule: each extra year of amortization cuts the payment a little and raises total interest a lot.
Since December 15, 2024, 30-year amortizations on insured mortgages have been available to all first-time homebuyers and all buyers of newly built homes; other insured purchases are generally capped at 25 years. Uninsured borrowers may have 30-year options through their lender, but insurer rules don't apply.
Payment frequency: regular vs. accelerated
The names sound interchangeable, but the totals are not:
- Monthly: one payment per month, 12 per year. The baseline.
- Biweekly (regular): the monthly payment is divided by 26 payments so you still pay the same annual total — barely changes the timeline.
- Accelerated biweekly: half the monthly payment every two weeks. Because there are 26 biweekly periods, you make the equivalent of 13 monthly payments a year — one extra payment that goes entirely against principal, often cutting roughly four years off a 25-year amortization.
- Weekly / accelerated weekly: the same logic on a weekly schedule.
For the $400,000 example, accelerated biweekly is $1,089.23 every two weeks instead of $2,178.45 a month. The price of the savings: each payment arrives sooner, so the budget needs room earlier in the month.
Your rate vs. the rate you're tested at
The payment you make follows your contract rate, but federally regulated lenders qualify the file at a higher rate — the greater of your contract rate plus two percentage points or 5.25% (OSFI's minimum qualifying rate, mirrored by CMHC for insured files). A 4.34% contract is therefore tested near 6.34%, which is the payment the lender must fit into your debt-service ratios. For the full mechanics, see our Ontario mortgage affordability guide.
Frequently asked questions
How is a Canadian mortgage payment calculated?
Canadian mortgages compound semi-annually. Convert the contract rate to a monthly rate with (1 + r ÷ 2)1/6 − 1, then apply the standard amortization formula. A $400,000 mortgage at 4.34% over 25 years costs about $2,178.45 per month.
What is the difference between accelerated biweekly and regular biweekly mortgage payments?
Accelerated biweekly is half the monthly payment every two weeks, which totals 13 monthly payments a year and can cut roughly four years off a 25-year amortization. Regular biweekly simply splits the same annual total across 26 payments with almost no time saved.
How much is the monthly payment on a $500,000 mortgage in Canada in 2026?
At 4.34% over 25 years, about $2,723.07 per month in principal and interest, with roughly $316,920 of total interest if the rate held for the full amortization. Your actual payment follows your rate, amount and amortization.
Does a longer amortization always cost more interest?
Yes. On a $400,000 mortgage at 4.34%, 30 years lowers the payment by about $199 a month versus 25 years but adds roughly $59,000 in lifetime interest.
What mortgage rate should I use when estimating payments in 2026?
Early October 2026 snapshots: lowest advertised 5-year fixed near 3.91% (money.ca), best-market high-ratio fixed around 4.34% (Ratehub), big-bank posted 5-year fixed rates roughly 4.59%–4.99%, and best 5-year variable near 3.40%. Use a current quote for decisions and a higher rate to stress-test the budget.
Sources and methodology
- money.ca: today's best mortgage rates (October 4, 2026)
- Ratehub: best-market and big-bank rate comparison (October 2026)
- chasingdreams.ai: October 1, 2026 rate snapshot (BoC 2.25%, prime 4.45%)
- OSFI: minimum qualifying rate for uninsured mortgages
- Financial Consumer Agency of Canada: down payment and amortization rules
- Finance Canada: 30-year amortization expansion (December 2024)
This article provides general information, not financial advice or a mortgage commitment. Payment examples use Canadian semi-annual compounding and a constant rate for illustration. Confirm current rates and qualification with your lender or a licensed mortgage professional.