Tools · Personal Finance

Mortgage renewal payment calculator

Your term is ending and the rate is not what it was. Enter the mortgage you took out and the rate you are being offered; see the balance you will renew, the new payment, the monthly increase, and what happens if you keep the old payment instead — with the arithmetic shown.

Imperium Post · Fixed-rate monthly payments with semi-annual compounding · Bank of Canada rates checked by Codex, 14 September 2026 · Entered amounts are not saved or sent

The mortgage you have now

Amount borrowed at the start of this term The balance when the expiring term began, not the original purchase price.

Rate on the expiring term Fixed-rate mortgages only; an average variable rate cannot reproduce the balance history.

Amortization when the term began (years) Enter the remaining repayment period at the start of this term.

Length of the expiring term (years) Scheduled payments, no prepayments; the same term length is used after renewal.

Payment frequency Monthly payments only.

Balance at renewal, if you know it (optional) From your renewal statement or mortgage portal. Overrides the estimate.

The renewal

Rate your lender is offering Preset 4.50% is an illustration, not a market rate — type the figure on your renewal statement or a broker's quote.

Amortization for the new term (years remaining) Leave blank to keep the original schedule. Extending lowers the payment and raises total interest.

New payment at four rates

Rate	Payment	Change	%	Interest over new term

If you keep the old payment instead

The working

Step	Amount

How the calculation works

This models a fixed-rate loan with monthly payments and semi-annual compounding. The monthly rate is (1 + annual rate ÷ 2)^1/6 − 1. At zero interest, payment is principal divided by repayment months. This is a specified convention, not a claim about every Canadian mortgage.

Payments are on schedule with no prepayments, fees, insurance or variable-rate changes. A statement balance overrides the estimate, including zero. The new term uses the same length as the expiring term. Interest stops at repayment; lender rounding and day-count differences are excluded.

A worked example

$500,000 at a nominal 4%, semi-annual compounding and 25-year amortization gives $2,630.10 monthly. After 60 payments, $435,269.58 remains. Renew at 6% over the remaining 20 years: $3,099.94 monthly, an increase of $469.84. These are mathematical examples, not rate offers.

Comparing an offer

Use your statement balance and quoted rate. Changing amortization changes payments and interest. The old-payment comparison does not establish lender approval. Check fees and contract terms separately.

Frequently asked

Does this support variable or biweekly loans?: No: constant fixed rate, monthly payments, semi-annual compounding only.
Is the posted rate an offer?: No. The 6.09% reference is the Bank of Canada posted five-year series dated September 9, 2026.
Can I enter zero?: Zero interest and a zero statement balance are supported. The original principal must be positive.

Sources checked by Codex, 14 September 2026

General information for the assumptions stated on this page; not personal financial or tax advice. Prepared with AI assistance by Claude; adapted and source-checked by Codex on 14 September 2026. Human factual review is not documented. Inputs stay in this page and are not saved or sent.