Mortgage Refinance Calculator
Refinancing swaps your mortgage for a new one, usually to get a lower rate. It costs money upfront, so the real question is how long the lower payment takes to pay those costs back, and whether you come out ahead over the whole loan. Put in your current loan and the offer you have, and the results update as you type.
How we calculate
Monthly payment. Both loans use the standard fixed-rate formula: payment = loan × r ÷ (1 − (1 + r)−n), where r is the yearly rate ÷ 12 and n is the number of monthly payments. Your current payment is worked out from the balance, rate and years left, so it leaves out taxes and insurance (escrow), which a refinance does not change.
Upfront costs. Closing costs plus points. Each point is 1% of the balance you are refinancing. If you add the costs to the new loan, the new loan is that much bigger and you pay interest on it.
Break-even. Upfront costs ÷ the monthly saving, rounded up to a whole month. If the new payment is not lower, you never break even on the payment alone.
Total interest. Everything you would still pay on each loan minus what you borrow: payment × n − loan.
Lifetime savings. What you would still pay on the current loan, minus everything you pay on the new one, minus upfront costs you pay in cash. A longer new loan can lower the payment and still cost more overall.
Common questions
When does refinancing make sense?
When you expect to stay in the home past the break-even month, and the lifetime savings are positive. A lower rate on its own is not enough if you move or sell before the costs are paid back.
Should I pay points?
Points lower the rate in exchange for cash upfront. Try the same offer with and without points: if the break-even moves past the time you plan to stay, the points are unlikely to pay off.
Is it better to add the closing costs to the loan?
It keeps cash in your pocket today, but you borrow more and pay interest on the costs for the whole loan. Tick "Add the costs to the new loan" to see the difference in total interest.
Why can a lower payment cost more overall?
Starting a new 30-year loan when your current one has, say, 22 years left spreads the balance over more years. Each payment is smaller, but you make many more of them, so total interest can rise.
Does this include taxes and insurance?
No. Property tax and homeowners insurance usually stay the same after a refinance, so they are left out of both payments.
Read our guide: Should I Refinance My Mortgage? 2025 Calculator + Guide
Not financial advice. This tool gives estimates from the numbers you enter, for information only. It is not financial, tax or legal advice. Rates, fees and prices change, so check with the provider, and talk to a qualified professional before you decide.