Mortgage renewal calculator

Both payments use the balance at renewal and the same remaining amortization. The old-rate payment is a counterfactual estimate at your previous rate, not a reconstruction of your original contract payment. This isolates the effect of the rate change.

Monthly i = (1 + r/2)^(1/6) − 1. Payment = P × i / (1 − (1 + i)^−n). At 0% interest, payment = P/n. Interest uses the opening balance each month. The model uses semi-annual compounding and unrounded intermediate amounts. The remaining number of monthly payments is full years × 12 plus additional months (0–11). The combined remaining amortization must be at least 1 month and may not exceed 40 years. If the remaining amortization ends before the selected term, the balance metric is shown at payoff instead of after the full selected term. Older saved and shared scenarios without a months value use zero additional months.

This is a payment comparison, not an approval or mortgage stress-test calculation. It excludes switching costs, discharge fees, penalties, new insurance charges, changes to the amortization, fixed-payment variable mortgages and lender-specific conditions. The chart assumes each rate continues beyond the selected term.

Compare a C$400,000 balance with 20 years remaining at 2.50% and 4.50%. The result shows the monthly change, the annual cash-flow difference and the projected balance after the new term.