A mortgage refinance break-even calculation estimates how long a lower payment takes to recover the cost of switching. The basic result divides the prepayment penalty and other entered fees by monthly payment savings.
That result is only one test. A longer replacement amortization can create a lower payment without lowering total cost, and a break-even month has little value if you expect to sell, refinance, or make a large prepayment before reaching it.
Gather current and proposed mortgage inputs
For the current mortgage, enter the outstanding balance, contract rate, and remaining amortization. For the proposed mortgage, enter the quoted rate and amortization. If fees and penalties will be added to the new loan, include them because financed costs increase principal and accrue interest.
Request a written payout quote from the current lender. A rough penalty estimate can be materially wrong when an interest rate differential depends on the lender's posted rates, discounts, comparison term, and contract method.
Calculate break-even without hiding amortization
If the new payment is lower, divide total switching costs by monthly savings and round up to the next month. That produces a payment-based break-even point. If the new payment is equal or higher, there is no payment-savings break-even even if another strategic reason for refinancing exists.
Keep the new amortization equal to the remaining amortization for a clean rate comparison. Then run a second case if extending amortization is under consideration. The gap between those cases reveals how much payment relief comes from slower principal repayment.
Decide whether the break-even period is useful
Compare the break-even month with the time you expect to keep the replacement mortgage. Add the risk of another move, sale, renewal, or refinance. Also compare prepayment privileges, portability, penalty method, fixed or variable structure, and lender service rather than treating rate as the only term.
FCAC recommends comparing the benefits of breaking a mortgage with the penalty, administration, appraisal, reinvestment, discharge, and new-mortgage setup costs. Ask whether waiting for renewal, porting, or a blend-and-extend option changes the outcome.
Stress-test the refinance result
Run the proposed quote, a slightly higher final rate, and a case with larger fees. Rate holds can expire and a property appraisal or legal review can change the transaction, so a decision that only works at one exact input has little margin.
Compare paying costs in cash with adding them to the mortgage. Then pin the clean same-amortization case before testing payment relief from an extension, so the cost of slower principal repayment remains visible.
Frequently asked questions
How do I calculate refinance break-even?
Divide the penalty and other switching costs by estimated monthly payment savings. Then compare that month with your realistic holding period.
What costs belong in a refinance calculator?
Include the prepayment penalty, discharge, legal, registration, appraisal, administration, setup, and any cash-back repayment that applies.
Can a lower refinance payment cost more overall?
Yes. Extending amortization or financing fees can lower the payment while increasing total interest and time in debt.
Sources and further reading
Mortgage rules and market data can change. Follow the links for current official information.