One penalty, calculated honestly
Mortgage penalty calculator
Estimate three months of interest. Fixed-rate penalties may instead use a larger interest rate differential.
Fixed uses the semi-annual equivalent monthly rate. Variable uses the v1 monthly-compounding contract assumption.
Educational estimate, not financial or mortgage advice. Confirm figures with your lender or a licensed mortgage professional.
Why IRD is explained, not calculated
An interest rate differential compares your contract rate with a lender-defined comparison rate for the time remaining in your term. Lenders can use posted-rate and discount inputs that are not present in a simple payment calculator. IRD math is planned for v2 for that reason; verify the lender's written quote.
Interest Act s.10 can cap the charge at three months' interest for a mortgage whose original term exceeded five years once five years have passed. The rule is specific and easy to oversimplify. Verify with your lender before acting.
Interest Act, R.S.C. 1985, c. I-15, s.10