Canadian Mortgage Comparison Calculator

The same rate gap, compounded over 25 years

Two rate quotes on identical terms don't just produce two monthly payments — they produce two different lifetime interest totals, and the gap between those totals grows faster than the rate gap itself because of compounding. On a C$750,000 purchase with 10% down (C$75,000), the base loan is C$675,000 at 90% loan-to-value, which requires CMHC insurance at the 85.01–90% tier, 3.10% of the loan: a premium of C$20,925, for a total insured mortgage of C$695,925 — the balance both rate scenarios below are compared against.

A 30-basis-point gap — the difference between a bank's posted-adjacent quote and a broker or credit-union quote — is common enough that it's worth running through this calculator before signing, rather than treating a C$118 monthly difference as immaterial.

Why the 30-year amortization scenario can cost more despite the lower payment

This calculator includes a third comparison by default: the same Rate A quote, stretched to a 30-year amortization. Two things change at once when amortization crosses 25 years on an insured mortgage. First, CMHC adds a 0.20% surcharge on top of the loan-to-value tier — 3.10% becomes 3.30% — so the 30-year scenario starts from a larger principal than the 25-year scenarios above: C$697,275 instead of C$695,925, a C$1,350 head start on interest before the amortization difference even applies.

The stress test still applies to a lender switch — usually

Comparing two lenders' rates isn't only a payment question; it's also a qualification question. OSFI's minimum qualifying rate requires every uninsured mortgage to qualify at the greater of the contract rate plus 2%, or a 5.25% floor, and Guideline B-20 states this is the standard rule for switching lenders too — in general, moving your mortgage to a new lender means re-qualifying at that higher rate, even if your existing payment history is perfect.

Two exemptions carved out since late 2024 change that, and they apply to different mortgage types. For an uninsured mortgage (20%+ equity), OSFI exempts a "straight switch" between federally regulated institutions from the stress test, effective November 21, 2024 — conditional on no increase to the remaining amortization, no equity take-out, and the unpaid balance increasing by no more than C$3,000 to cover transaction costs like penalties or fees. For an insured mortgage, the Department of Finance's parallel measure removes the stress test on portfolio-insured straight switches under the same no-equity-take-out, same-amortization conditions, effective December 16, 2024. Neither exemption applies if you're increasing your amortization, pulling out equity, or moving by more than the C$3,000 transaction-cost allowance — any of those turns the move back into a fully re-qualified, stress-tested mortgage.

This calculator compares payments and interest across the rates you enter; it does not check whether your specific move qualifies as a straight switch. Confirm eligibility with both lenders before assuming the lower rate you're comparing is actually available to you stress-test-free.

How big a rate gap is realistic to enter here right now

It helps to know what you're comparing against. The Bank of Canada's own posted-rate series put the chartered banks' posted 5-year conventional mortgage rate at 6.09% as of mid-September 2026 — that is the banks' sticker rate, not the discounted rate most approved borrowers actually receive, so entering 6.09% as "Rate A" here would overstate what a real quote looks like. The Bank of Canada's target for the overnight rate — the policy rate that anchors variable-rate pricing — has stood at 2.25% since its most recent cut, for context on why variable quotes are priced where they are; it does not set fixed mortgage rates directly.

Enter your two actual quoted rates — never a posted or advertised "as low as" rate — for the comparison above to mean anything: the C$35,520 gap in the first example came from a realistic 0.30-point spread between two contract quotes, not from comparing a discounted rate to a bank's sticker rate.

Switching mid-term isn't the same comparison as switching at renewal

The straight-switch exemption covered above applies at renewal, when the existing term ends. Comparing a new lender's rate against your current one MID-term is a different calculation, because breaking a closed mortgage contract early normally triggers a prepayment penalty. FCAC states plainly that this fee "can cost thousands of dollars," and that penalty can erase some or all of the savings a lower rate would otherwise deliver — so the comparison that matters isn't just rate versus rate, it's rate savings versus penalty cost.

FCAC's own briefing on prepayment penalties describes the penalty as usually the greater of three months' interest or the Interest Rate Differential (IRD), with the IRD usually based on the lender's posted rates — which can shift substantially whenever a bank changes its posted rate. An open mortgage can be prepaid or paid off without any penalty at all, which is the tradeoff for its typically higher rate. FCAC's suggested ways to reduce the penalty before switching: use your annual lump-sum prepayment privilege first to shrink the balance being penalized, wait until closer to term end if the penalty would be large, or ask about porting the mortgage instead of breaking it outright.