Mortgage Refinance Calculator
Compare your current mortgage to a refinance, including closing costs and the break-even point.
Free to use No sign-up needed Updates as you type
How the mortgage refinance calculator works
Refinancing swaps your current mortgage for a new one — usually for a lower rate, a shorter term, or both. The calculator sets your existing payment beside the proposed one and adds the closing costs of making the switch.
Because those costs take time to recoup, the headline number is the break-even month: when your monthly savings finally repay them. It also compares total interest on both loans, so a lower payment that simply re-stretches the balance won't mislead you.
Worked example: with current balance of $250,000, current rate of 8.25% and years left on current loan of 27, the mortgage refinance calculator shows monthly payment savings of $234.61.
- Current payment
- $1,928.20
- New payment
- $1,693.59
- Break-even
- 19 mo
- Net savings after 7 yrs
- $13,004
The formula
New monthly payment uses the standard amortization formula on the refinanced balance, rate, and term. Break-even months equal total closing costs divided by the monthly payment reduction. Lifetime interest is summed separately for each loan and subtracted to show the net difference. Net savings after the years you plan to keep the loan compare (payments made + balance still owed) on each path, with closing costs added to the refinance — counting the balance matters because a stretched new loan pays down more slowly.
How every calculator here computes, what it assumes and how the defaults stay current: our methodology.
- Both loans are assumed fixed-rate; an adjustable starting rate would understate later payments once it resets.
- Closing costs are paid upfront in cash, not rolled into the new balance, which would change the break-even.
- Break-even ignores the time value of money and any return you could earn on the cash spent on fees.
- Property taxes and homeowners insurance are excluded, since escrow amounts are unchanged by refinancing.
- Net savings are measured at the year you enter for keeping the loan; lifetime interest assumes both loans run to term.
Reference data
Current figures behind this tool: FHA Mortgage Insurance (MIP) Rates 2026, Fannie Mae LLPA Matrix 2026.
Results are estimates for educational purposes and are not financial advice. Confirm exact figures with your lender or a licensed advisor.
Questions about the mortgage refinance calculator
Does refinancing restart my mortgage clock back to 30 years?
It can, and that is the hidden cost. A new 30-year loan resets the term, so even at a lower rate you may pay more total interest by stretching the balance over more years.
To avoid that, refinance into a term matching the years you have left, or make extra principal payments to offset the reset.
How much does a rate drop need to be before refinancing is worth it?
There is no universal threshold; it depends on your balance and fees. A larger loan earns back closing costs faster, so even a cut of half a percentage point can pay off, while a small balance may need a full percentage point or more.
Run the break-even: if you will keep the home well past that month, the refinance makes sense.
Can I refinance if my home value has dropped since I bought it?
Possibly, but a lower appraisal raises your loan-to-value ratio, which can trigger mortgage insurance or disqualify you above roughly 80 percent. Some borrowers bring cash to closing to shrink the balance, and certain streamline programs waive a fresh appraisal entirely. The calculator assumes you already qualify at the rate you enter.
Is my information saved or shared?
No. Every calculation runs entirely in your browser. We never store, transmit or sell the numbers you enter.
How does refinancing a mortgage work?
Refinancing replaces your current mortgage with a new one — ideally at a lower rate or shorter term. It carries closing costs, so it pays off once your monthly savings recover those costs; that recovery point is the break-even shown above.
Sources
- CFPB — Loan Estimate explainer
- CFPB — Interest rate vs APR
- Freddie Mac — Primary Mortgage Market Survey (weekly average rates)
How the figures on this site are calculated and tested: methodology · editorial policy.
Should I Refinance Calculator
Decide if refinancing is worth it by weighing monthly savings against closing costs and time in the home.
Mortgage Payoff Calculator
See how extra monthly payments shorten your mortgage and slash the interest you pay.
Mortgage Points Calculator
Decide whether buying discount points to lower your rate pays off, and how long it takes.
Blended Rate Mortgage Calculator
Find the combined effective rate across a first mortgage and a second loan or HELOC.
Mortgage Debt Consolidation Calculator
See whether rolling high-interest debt into your mortgage lowers your total monthly cost.
Cash-Out Refinance Calculator
Refinance for more than you owe and take the difference in cash — new payment, cash in hand and new LTV.