Mortgage Renewal Calculator Canada 2026

Your mortgage term and your amortization are different things. The amortization is how long it takes to pay the mortgage off in full — commonly 25 years. The term is the length of your contract with one lender, usually one to five years. When the term ends, the balance does not come due; it renews. Renewal is simply the point at which you sign a new contract for the next term, and it is the one moment where switching lenders costs you no prepayment penalty.

That penalty-free window is the reason renewal is worth calculating rather than signing. Your existing lender will usually mail an offer four to six months before maturity. That offer is a starting position, not a market rate — it is priced on the assumption that most borrowers accept it without comparing. The gap between a renewal offer and the best available rate is typically a few tenths of a percent, which sounds small and is not: on a $400,000 balance over a five-year term, 0.5% is roughly $10,000 in additional interest.

The practical timeline is 120 days. Most Canadian lenders will hold a rate for 90 to 120 days at no cost, so starting four months out lets you secure today's rate while continuing to shop. If rates fall before you close, most lenders will honour the lower rate; if they rise, you keep the hold. Waiting until the final month removes that option and leaves you negotiating against a deadline.

One thing the calculator cannot tell you is whether a switch will be approved. Since 21 November 2024, OSFI no longer requires the minimum qualifying rate on a straight switch — moving your existing balance and amortization to a new lender without increasing either. Insured borrowers were already exempt. That removed the single biggest barrier to shopping a renewal. Two caveats still bite: the exemption is not a free pass, because the new lender still underwrites your income and credit in full (just at your contract rate rather than the stress-tested one), and individual lenders may still apply their own stress test by choice — BMO reinstated one in December 2024. Increase the balance or stretch the amortization and it stops being a straight switch, at which point full refinance qualification applies.

To calculate a renewal by hand, you need three numbers: your remaining balance, your remaining amortization, and the rate on offer. Canadian fixed mortgages compound semi-annually by law, so the first step is converting the quoted annual rate to a true monthly rate — (1 + rate ÷ 2)^(1∕6) − 1 — and the second is the standard amortization formula on your balance over the months remaining. That conversion is the part almost every generic calculator gets wrong, and it is the math this tool does for you.

A worked example makes the stakes concrete. Take a $400,000 balance with 20 years of amortization remaining. At a renewal offer of 4.59%, the payment is $2,541 a month and the interest paid over a five-year term is about $83,500. At 4.04% — a market-best rate rather than the mailed offer — the payment is $2,425 and five-year interest is about $73,300. The 0.55% gap looks small on paper; it is $115 every month and roughly $10,300 over the term, on a mortgage that renews penalty-free either way. That difference is what the renewal letter is priced hoping you will not calculate.