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Refinance Calculator

Compare your current mortgage against a new rate and term to see the new monthly payment, how much you save each month, when the closing costs pay for themselves, and the effect on total interest.

Current loan

New loan

Everything runs in your browser. Nothing is uploaded.

New monthly payment
1,719.44
was 1,978.98 per month, 259.54 less
259.54
Monthly savings
16
months (1 year 4 months)
73,861.03
Lifetime savings
77,861.03
Interest saved
1,978.98
Current payment
4,000.00
Closing costs

Estimates cover principal and interest on the balance you enter and exclude taxes, insurance, and any points rolled into the loan. Break-even assumes the closing costs are paid up front. Confirm exact figures with your lender.

How to calculate refinance savings

  1. Enter your current loan

    Type the balance you still owe, your current interest rate, and the number of years or months left on the loan.

  2. Enter the new loan

    Type the new interest rate and term you are offered, and the closing costs you would pay to refinance.

  3. Read the comparison

    The new monthly payment, monthly savings, break-even point, and change in total interest update instantly as you type.

Why use this tool

Break-even in months

The break-even point divides your closing costs by the monthly saving, so you see exactly how long it takes for a lower payment to earn back the cost of refinancing.

Old and new payment side by side

Both payments come from the same amortization math, so the monthly saving is a fair comparison rather than a rounded guess.

Lifetime interest, not just payment

A lower payment can still cost more over a longer term. The calculator shows the change in total interest and flags when a smaller payment adds to the lifetime cost.

Handles the case where it does not pay

If the new payment is higher, or the costs outlast the loan, there is no break-even. The tool says so plainly instead of printing a misleading number.

Years or months, 0% supported

Enter either term in years or months and switch between them without losing your figures. A zero interest rate divides the balance evenly instead of erroring.

Private by default

Loan balances are personal. Every figure is calculated on your device, and nothing is uploaded, stored, or logged.

About this tool

This refinance calculator answers one question: is it worth swapping your current mortgage for a new one? It takes the balance you still owe, then works out the monthly payment on your current rate and remaining term and the payment on the new rate and term using the same amortization formula. The difference between the two is your monthly saving. Divide the closing costs by that saving and you get the break-even point, the number of months you have to keep the loan before refinancing has paid for itself.

The payment is only half the story, so the calculator also compares total interest over the life of each loan. Refinancing to a lower rate but a fresh long term can drop the monthly payment while raising what you pay overall, and the tool flags that instead of hiding it. Lifetime savings folds the closing costs back in, so the headline figures reflect the real cost of the switch. If the new payment is not lower, or the costs would take longer to recoup than the loan lasts, there is no break-even and the calculator says so.

Use it to sanity-check a lender quote before you commit, or to compare two offers. For sizing a brand new purchase see the mortgage calculator, and for any fixed loan without taxes or insurance the loan calculator covers the same amortization math. Figures here cover principal and interest only and exclude taxes, insurance, and points rolled into the balance, so confirm exact numbers with your lender. Every calculation runs in your browser as you type, and nothing is uploaded.

Frequently asked questions

How is the break-even point calculated?
The break-even point is your closing costs divided by the monthly saving, rounded up to a whole month. If refinancing saves you 250 a month and costs 4,000 to close, you break even after 16 months. Keep the loan past that point and the refinance comes out ahead.
What if the new payment is higher than my current one?
Then there is no break-even, and the calculator shows a note instead of a number. A lower interest rate can still raise the monthly payment when the new term is shorter than the time left on your current loan.
Why does it show a saving each month but more interest overall?
Refinancing to a fresh, longer term spreads the balance over more payments, which lowers each payment but adds more interest across the full life of the loan. The tool compares total interest for both loans and flags this so a lower payment does not mislead you.
What does the calculator not include?
It compares principal and interest on the balance you enter. Property tax, home insurance, mortgage insurance, and points or fees rolled into the new balance are not modeled, so treat the result as an estimate and confirm exact figures with your lender.
Can I enter the term in months?
Yes. Switch either term between years and months and the values convert as you toggle. This is useful when only a partial number of years is left on your current loan, such as 22 years and 4 months.
Is my data uploaded anywhere?
No. Your balance, rates, term, and closing costs never leave your device. All calculations run in your browser and nothing is sent to a server, stored, or logged.

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