Refinancing your mortgage can be one of the most impactful financial decisions you make — or one of the most expensive mistakes. The difference comes down to three numbers: how much your payment drops, how much it costs to refinance, and how long you plan to stay in the home. This calculator gives y...
YOUR CURRENT LOAN
NEW LOAN TERMS
Enter your Current Loan Balance — the amount you still owe on your mortgage, not the original loan amount.
Enter your Current Monthly Payment — the principal and interest portion of your current payment (not including taxes and insurance).
Enter your Current Interest Rate — the rate on your existing mortgage.
Enter the New Interest Rate being offered — get this from your lender or use current market rates.
Enter Closing Costs — your lender will provide a Loan Estimate. Typical costs are $3,000–$8,000. Enter 0 for a no-closing-cost refinance.
Review your new payment, monthly savings, and break-even point. If you plan to stay longer than the break-even, refinancing likely makes sense.
Sarah has a remaining mortgage balance of $280,000 at 7.5% interest with a monthly payment of $2,100. Her lender offers a refinance at 6.25% for 30 years with $4,500 in closing costs. New Payment = $280,000 × (0.005208 × 1.005208^360) / (1.005208^360 - 1) = $1,724. Monthly Savings = $2,100 - $1,724 = $376/month. Break-Even = $4,500 / $376 = 12 months. Sarah plans to stay for 10+ years, so she will recover the closing costs in just 12 months and save $376/month for the remaining 9+ years — a clear win.
| NAME | FORMULA | DESCRIPTION |
|---|---|---|
| New Monthly Payment | M = P × r(1+r)ⁿ / ((1+r)ⁿ - 1) | P = loan balance, r = monthly rate, n = total new payments |
| Monthly Savings | Savings = Current Payment - New Payment | Monthly cash flow improvement from refinancing |
| Break-Even Months | Break-Even = Closing Costs / Monthly Savings | Months until cumulative savings exceed upfront costs |
| Lifetime Savings | Lifetime = (Old Payment × n) - (New Payment × n) - Closing Costs | Total savings over the full new loan term |
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Last updated: April 25, 2026 · Formula verified by EagleCalculator team · Eagle-eyed accuracy for every calculation.