Mortgage Refinance Calculator
See whether refinancing saves you money: compare payments, monthly savings, and how long it takes to recoup closing costs.
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New monthly payment (P&I)
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Principal and interest only; taxes and insurance are extra.
How it works
Both payments come from the standard amortization formula:
Where B is the loan balance, r the monthly rate, and n the number of payments. Monthly savings is simply the old payment minus the new one, and the break-even point is:
If the new payment is not lower than the old one, refinancing cannot pay for itself — the calculator will say so plainly.
Frequently asked questions
What is the break-even point of a refinance?
It is the number of months it takes for your monthly savings to add up to what you paid in closing costs. If you plan to sell or move before the break-even point, the refinance costs you money instead of saving it.
How much lower should the new rate be to make refinancing worth it?
The old rule of thumb is at least 0.75 to 1 percentage point lower, but the real test is the break-even math: monthly savings times the months you will keep the loan must exceed the closing costs.
Does refinancing restart the loan clock?
Often yes. Refinancing into a new 30-year loan resets your payoff date, which can mean paying more total interest even with a lower rate. Compare total interest, not just the monthly payment, before deciding.
What are typical refinance closing costs?
Usually 2% to 5% of the loan amount, covering origination fees, appraisal, title insurance, and recording fees. Some lenders offer no-closing-cost refinances, but they typically charge a slightly higher rate instead.