Mortgage · Renewal
Renewal payment shock calculator.
When a Canadian mortgage term ends, the balance is re-priced at whatever rate you are offered, over the amortization you have left. This shows the new payment against the old one, the yearly cost difference, and what stretching the amortization would do to both the payment and the total interest.
Same balance, same remaining amortization, new rate. The only thing that moves the payment is the rate, so a rise from a low rate can lift it by a third or more. Extending the amortization softens the jump but adds interest over the longer life of the loan.
Inputs
Your new payment
Fill the form and press Calculate.
How the numbers are worked out
Payment on balance B over n months at monthly rate i is B × i ÷ (1 − (1 + i)−n). The old and new payments use the same balance and the same n, so the difference is purely the rate (and its compounding).
Compounding. Section 6 of the federal Interest Act requires a mortgage to state its rate “calculated yearly or half-yearly, not in advance”. Fixed-rate mortgages in Canada conventionally use half-yearly compounding, so the monthly rate is (1 + rate ÷ 2)1/6 − 1. Variable-rate mortgages are conventionally quoted with monthly compounding, so the monthly rate is rate ÷ 12. That variable convention is industry practice, not something the Act spells out, which is why each rate has its own selector. Check your mortgage documents.
Worked example. $400,000 over 25 years. At 2.00% fixed (half-yearly) the payment is $1,693.80; at 5.00% fixed it is $2,326.42. That is $632.62 more a month, $7,591.38 more a year, or 37.35%. Stretching to 30 years at 5.00% brings the payment to $2,134.76 (still $440.96 above the old one), but total interest over the remaining life rises from $297,925.98 to $368,514.58, about $70,588.60 more.
No market rates. Every rate is typed by you. Nothing here forecasts what a lender will offer.
Source, read 30 September 2026: Interest Act, R.S.C. 1985, c. I-15, s. 6, Justice Laws Website (laws-lois.justice.gc.ca/eng/acts/I-15/section-6.html).
Frequently asked questions
Why does my payment jump so much at renewal?
Early in a mortgage most of each payment is interest, so the payment is very sensitive to the rate. Going from 2% to 5% on the same balance and amortization raises the payment by roughly 37%.
Does extending the amortization save money?
It lowers the monthly payment but you pay interest for longer, so total interest goes up. The calculator shows both numbers side by side so the lower payment is not mistaken for a saving.
What if my variable-rate payment never changed?
Some variable mortgages hold the payment fixed while the interest portion moves. Enter your actual current payment in the optional box, and see the trigger rate calculator for the point where that payment stops covering interest.
Can I avoid the shock by blending?
Only if you are renewing early. A blend-and-extend mixes your old rate with today's rate over a longer term; try the blend and extend calculator.
Estimate only — confirm with your lender
This tool illustrates the payment arithmetic. It does not know your lender's terms, rounding, fees or the rate you would really be offered, and your lender decides whether an amortization extension is available. Confirm every figure with your lender before you sign.