How this calculator works
Refinancing swaps your existing mortgage for a new one β with your current lender or a new one β usually on your existing outstanding balance (or higher, if accessing home equity). The calculator works out your monthly payment on both the current and new deal, then compares them:
Monthly saving = current monthly payment − new monthly payment
If the new deal has fees β appraisal, legal, discharge, and/or a prepayment penalty for breaking your current term early β those fees eat into your saving before you're better off overall. The calculator finds yourbreak-even month (fees divided by the monthly saving, rounded up) and a lifetime saving figure over the shorter of your two remaining amortization periods, after fees. If the new deal doesn't actually lower your payment, there's no break-even point to find, and the calculator says so clearly.
Worked example
Say you have $350,000 outstanding, currently on a 6% rate with 22 years remaining. You're offered a new deal at 4.8% over a fresh 25-yearamortization, with $1,500 in fees. The new deal noticeably lowers your monthly payment, and that saving typically recoups a fee of this size within a matter of months β with a substantial lifetime saving over the comparison term once fees are subtracted. Bear in mind part of any saving reflects stretching the loan back to a fresh 25-year amortization rather than the 22 years remaining β worth weighing alongside the monthly saving.
What affects your result
- The rate gap β the difference between your current and new rate is the single biggest driver of your monthly saving.
- New deal fees, including any prepayment penalty β a lower rate with a large IRD penalty for breaking your term early can take much longer to break even than waiting until your term ends.
- Amortization changes β resetting to a longer amortization lowers the monthly payment further but increases total interest paid over the life of the loan.
- Fixed vs variable rate type β remember that fixed-rate mortgages compound semi-annually by law, while variable-rate mortgages compound monthly, at the identical quoted rate.
A note on accuracy
This calculator compares principal-and-interest payments only, using unrounded figures internally with rounding applied solely for display. It does not automatically calculate an Interest Rate Differential (IRD) penalty for breaking your current term β get an exact payout quote from your current lender and add it to the new deal fees field if applicable. For general guidance on refinancing, seeFinancial Consumer Agency of Canada.