Mortgage Refinance Calculator

Should you refinance? See your true break-even, not the naive one lenders show, plus the term-reset trap and the exact rate where a refi starts paying off. All math runs in your browser; your numbers never leave this computer.
🔓 Sells nothing · recommends no lender or products · no ads, no affiliates, no upsell, just your own numbers, kept 100% private.
Your data:
ℹ️ How saving, downloading & updating work — click to expand
  • Auto-save, everything you type is remembered in this browser automatically. Nothing is ever uploaded; clearing your browser data erases it.
  • ⬇ Download file / ⬆ Load file, save your numbers as one small PrivateCalcs data file that works across all the calculators in this family, each tool fills in what it recognizes (basics like filing status and state carry over automatically), keeps its own section, and leaves the other tools' sections untouched. Back it up or move it between devices freely; older single-tool files still load.
  • 📥 Download this tool, saves the entire calculator as one HTML file. Open it any time with no internet, it makes no network calls at all, so it's fully private and works forever.
  • 🔄 Get latest version, refreshes to the newest published version. Your saved data is not erased (but hit ⬇ Download file first if you want to be extra safe).

Your current loan required

Grab all three numbers from your latest statement. Use only the principal & interest part of the payment, leave out the escrow portion (taxes and insurance don't change when you refinance the loan itself). Assumes a fixed rate on both loans.
Not sure? Look it up free on Zillow or Redfin, then type the number here. This tool never sends your address (or anything else) anywhere.

The new loan required

Typical closing costs run 2–5% of the loan. A discount point is an upfront fee of 1% of the loan that "buys" a lower rate, enter the points here and the already-discounted rate above, and the break-even math weighs whether they were worth it.
Checking this is the fairest comparison: same money out of your pocket every month, so the lower rate shows up purely as a faster payoff and less interest, no payment-stretching illusion.

Your plans the deciding factor

This matters more than the rate. Closing costs are paid up front, but the savings trickle in monthly, if you sell or refinance again before the savings catch up, the refi loses money no matter how good the rate looked.

The verdict

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True break-even
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Saved by the time you sell
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Saved over the loan's life
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Current loan paid off
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New loan paid off
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Refi worth it below
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Why "true" break-even? (the honest math)
Most refi calculators divide closing costs by the monthly payment drop and call it break-even. That's misleading: a new 30-year loan almost always has a lower payment than a loan you're 6 years into, even at the same rate, because it stretches the debt back out. The payment drop isn't all savings; part of it is just slower payoff.

This tool compares your whole financial position instead, month by month: every dollar you'd pay under each loan plus the loan balance you'd still owe. The true break-even is the month the refi actually puts you ahead, cash and equity combined. That's the number that should drive the decision, and it's usually later than the naive one.

Are you ahead yet? — net benefit over time

Year by year

"Cash-flow saved" is simply how much less you paid that year under the new loan. "Net benefit" also counts the loan balances, it's your true running position, and it starts in the hole by exactly your closing costs.