Refinance Calculator
Compare your current loan against a refinance offer, including monthly savings and breakeven point.
Your current loan
Refinance offer
Current monthly payment
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New monthly payment
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Monthly savings
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Breakeven point
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Lifetime interest change
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| Current loan | New loan | |
|---|---|---|
| Total interest remaining | — | — |
| Total cost to pay off | — | — |
How this calculator works
Enter your current loan's remaining balance, rate, and remaining term, then the new rate, term, and closing costs from a refinance offer. The calculator computes both loans' monthly payments using standard fixed-rate amortization, then compares them on three things: how much your monthly payment changes, how many months it takes for that monthly savings to pay back the closing costs (the breakeven point), and how total interest paid over the life of each loan compares.
That last comparison matters because a refinance can lower your monthly payment while still costing more overall — if the new loan resets the clock to a fresh 30-year term, you're paying interest for longer, which can outweigh the benefit of a lower rate. This calculator shows both the monthly-payment view and the total-cost view side by side, so a lower payment doesn't hide a higher lifetime cost.
Worked example
$300,000 remaining at 7.0% with 25 years left costs $2,120/month, with $336,101 in interest left to pay. Refinancing to 6.0% on a fresh 30-year term drops the payment to $1,799/month — a $322/month saving that pays back $5,000 in closing costs in about 15.5 months. But because the new 30-year term restarts the clock, total interest actually rises to $347,515 — about $11,413 more than sticking with the current loan, plus the $5,000 closing costs. The monthly payment looks like a clear win; the lifetime cost tells a different story — try matching the new term closer to 25 years instead of 30 to see how that changes the picture.
Frequently asked questions
Why would a lower rate ever cost more overall?
Refinancing usually resets the clock — a fresh 30-year term restarts amortization from month one, even if you were already 5 or 10 years into your original loan. A lower rate lowers your monthly payment, but stretching the payoff back out to 30 years can mean paying interest for longer overall than if you'd kept your original loan. This calculator shows both effects so you can see the real trade-off, not just the monthly payment.
What's a good breakeven period for a refinance?
A common rule of thumb is comparing the breakeven month (how long until your monthly savings cover the closing costs) to how much longer you plan to stay in the home or keep the loan. If you'll move or pay it off before breakeven, the refinance likely isn't worth the closing costs.
Should I match my new loan's term to my remaining term instead of resetting to 30 years?
It's worth comparing both. Matching the new term closer to your remaining years (say, a 20-year refinance instead of resetting to 30) usually raises the monthly payment but avoids stretching the payoff timeline out — often the better move if lifetime interest matters more to you than the lowest possible monthly payment. Try both term lengths here to compare.
Does this include closing costs rolled into the loan?
No — this calculator treats closing costs as a separate one-time, out-of-pocket amount, not added to the new loan balance, to keep the interest comparison clean. If your lender rolls closing costs into the loan instead, your actual new balance (and monthly payment) would be slightly higher than shown here.
Does this work offline?
Yes — every calculation is standard loan amortization math done in your browser, so it keeps working without an internet connection once loaded.