How to use this calculator
- Enter old monthly payment, new monthly payment, upfront refinancing costs.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
Assumes constant payment savings. Remaining balances, term differences, tax, opportunity cost and future sale dates are not included.
Worked example
With old monthly payment = 1200, new monthly payment = 1000, upfront refinancing costs = 3000, simple break-even months is approximately 15.
What the result means
A lower payment can result from a longer term and does not necessarily reduce lifetime borrowing cost.
Common questions
How should I interpret simple break-even months?
A lower payment can result from a longer term and does not necessarily reduce lifetime borrowing cost.
What should I check before using this result?
Assumes constant payment savings. Remaining balances, term differences, tax, opportunity cost and future sale dates are not included.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.