Mortgage Refinance Calculator

See whether refinancing your mortgage is worth it. Enter your current loan and a new rate and term, then press Calculate to compare payments, lifetime interest and the break-even month.

Written by TopicDrill Editorial Team·Updated June 2026

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Your loan details

Compare your current mortgage with a new one, then press Calculate.

$
$

Monthly savings

$300

lower each month · break-even in 16 mo

Current payment$1,890
New payment$1,590
Lifetime interest saved$39,875

Cumulative savings after costs

Net savings Break-even
-$4.5k$22.5k$49.4k$76.4k$103.4k0 yr15 yr30 yr

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How the mortgage refinance calculator works

The tool builds two amortizing loans on the same remaining balance: your existing mortgage at its current rate and time left, and a new loan at the rate and term you are considering. It compares the monthly payment of each and totals the interest you would pay over the full life of both.

The chart tracks cumulative savings. It starts below zero by the amount of your closing costs and rises by your monthly saving each month. The point where the line crosses zero is your break-even month, the moment the refinance has finally paid for itself.

A worked example

Say you owe $280,000 at 6.8% with 27 years left, and you refinance into a 30-year loan at 5.5% with $4,500 in closing costs. The payment falls noticeably, and dividing the closing costs by that monthly saving tells you roughly when you break even. Stay in the home well past that month and the refinance is a clear win; sell before it and you may lose money.

Things to keep in mind

The figures assume you keep each loan to term and ignore taxes and any rate buydown points, so use them as a guide rather than an exact promise. Shop several lenders, since the rate and fees vary a lot. For background on the process, see the CFPB owning-a-home guide. If you also want cover for the loan, see our mortgage protection calculator.

Frequently asked questions

When does refinancing make sense?

Refinancing usually pays off when the new rate is low enough that your monthly savings recover the closing costs well before you plan to sell or move. A lower rate, a shorter time to break even, and staying in the home past that point all strengthen the case.

What is the refinance break-even point?

It is the number of months it takes for your accumulated monthly savings to equal the upfront closing costs. Divide the closing costs by the monthly saving to get a quick estimate. After that month you are genuinely ahead; before it, the refinance has not yet paid for itself.

Why might my monthly payment drop but total interest rise?

Resetting to a longer term spreads the balance over more payments, so each one is smaller even at a similar rate, yet you pay interest for more years overall. This tool shows both the monthly saving and the lifetime interest so you can see that trade-off clearly.

Are closing costs always paid upfront?

Not always. Some lenders offer a no-closing-cost refinance by rolling the fees into the balance or nudging the rate up. That removes the upfront hit but raises your effective cost, so compare the true rate, not just the headline payment.

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