Mortgage Interest Calculator
How much interest you will pay on a mortgage: over the term you sign for, over the whole amortization, per $100,000 borrowed, and in the first payment. And what the same mortgage costs a quarter or half a point either way.
The rate starts at the average on new uninsured 5-year mortgages in July 2026, from the Bank of Canada (all mortgage rates).
How long the rate is set for
Interest over the 5-year term
$104,784
63% of what you pay during the term. $20,957 per $100,000 borrowed.
Monthly payment
$2,764.59
Interest in the first payment
$1,853.57
Interest over 25 years
$329,376
Balance at the end of the term
$438,909
A quarter point more, 4.74%, costs $5,992 more over the term and $69.88 more a month.
Semi-annual compounding, the rule for every Canadian mortgage. The amortization figure assumes the same rate at every renewal. Property tax, insurance and fees are not included.
The Same Mortgage at Nearby Rates
| Rate | Monthly payment | Interest over the term | Balance at renewal | Interest over 25 years |
|---|---|---|---|---|
| 3.99% | $2,627.39 | $92,837 | $435,194 | $288,217 |
| 4.24% | $2,695.56 | $98,804 | $437,071 | $308,667 |
| 4.49%your rate | $2,764.59 | $104,784 | $438,909 | $329,376 |
| 4.74% | $2,834.47 | $110,776 | $440,708 | $350,340 |
| 4.99% | $2,905.18 | $116,779 | $442,468 | $371,554 |
Each row is the same $500,000 over 25 years, with the rate held for the whole amortization in the last column. Last month's average rates are on our mortgage rates page.
Interest and Principal in Each Year of the Term
| Year | Interest | Principal | Interest share | Balance at year end |
|---|---|---|---|---|
| 1 | $22,017 | $11,158 | 66% | $488,842 |
| 2 | $21,511 | $11,664 | 65% | $477,178 |
| 3 | $20,981 | $12,194 | 63% | $464,984 |
| 4 | $20,427 | $12,748 | 62% | $452,236 |
| 5 | $19,848 | $13,327 | 60% | $438,909 |
| Term | $104,784 | $61,091 | 63% | $438,909 |
The full schedule, payment by payment, is on the amortization schedule calculator.
How Mortgage Interest Is Calculated in Canada
By law, a fixed-rate mortgage in Canada is compounded semi-annually, not monthly: the quoted rate is applied in two half-year steps, and the monthly rate is the one that gives the same result. At 4.49% that monthly rate is 0.3707%, a little under a twelfth of the annual rate, which is why a Canadian mortgage costs slightly less interest than a US one at the same quoted rate. Each month the interest is that rate times the balance still owed; the rest of the payment reduces the balance, and the next month's interest is charged on the smaller amount. Variable-rate mortgages compound monthly at most lenders, and their rate moves with prime.
Why the Term Figure Is the One to Watch
The interest over the amortization is the striking number, often close to the amount borrowed, but it assumes the rate never changes for 25 years. Nobody pays that rate for that long: the mortgage renews every term, at whatever rates are then, and most are paid down faster through prepayments, moves and refinancing. The interest over the term is what the rate you are signing for will actually cost you, and it is the figure to compare between two offers: a quarter point on a typical mortgage is several thousand dollars over five years. The balance at the end of the term is what the next rate will apply to.
Paying Less Interest
A lower rate is the obvious lever and the one worth negotiating hardest, since it applies to every dollar for the whole term. A shorter amortization raises the payment but cuts the interest sharply, because the balance falls faster and there is less of it to charge on. Prepayments do the same thing on your own schedule: our prepayment calculator and payment frequency calculator put figures on each, and the mortgage payment calculator works out the payment itself.
Today's Mortgage Rates from Lenders
This calculator works with whatever rate you enter. Compare it with the rates lenders are offering right now, fixed and variable, by term. Change the price, down payment or location to match your purchase.
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