Quick guide
How to use this calculator
- Enter the figures from the offers, statement, or transaction estimate you want to examine.
- Keep every amount in one consistent currency and use the rate and period convention shown by each label.
- Compare the result with the visible assumptions before making a decision.
Calculation method
Calculation method
Simple break-even months = refinancing costs ÷ positive monthly payment savings.
Calculations retain full precision internally and round only for presentation. Invalid, non-repaying, out-of-range, and numerically unreliable inputs are rejected.
Worked example
Practical example
A 4,000 cost with 200 of monthly savings has a simple payment break-even of 20 months.
Simple break-even months = refinancing costs ÷ positive monthly payment savings.
Supported inputs
Precision and limits
Visible limits
Amounts are capped at 1e12, rates at 1000%, and mortgage terms at 1,200 whole months.
International scope
No currency, country, tax system, fee schedule, lender policy, regulated APR definition, or market rate is assumed.
Decision boundary
These results are mathematical comparisons of entered scenarios, not an offer, approval, legal disclosure, valuation, or recommendation.
Calculator-specific assumptions
This simple break-even does not discount cash flows or treat principal reduction as a cost. Full-schedule borrowing costs are shown separately.