Mortgage Refinance Calculator

A mortgage refinance calculator estimates the principal-and-interest payment on your current loan and on a hypothetical new loan, then compares the difference. National Mortgage Center’s calculator also illustrates break-even timing (estimated costs ÷ estimated monthly difference), five-year cash difference, remaining interest, and a savings-horizon table. It is educational only and is not a rate quote, Loan Estimate, or approval.

Have your remaining loan balance, current interest rate, remaining term, a new rate assumption, a new term, and estimated closing costs. For cash-out, add the cash amount. Home value is optional and is used only to illustrate loan-to-value. Taxes, insurance, HOA, and mortgage insurance are not included in the P&I figures.

The simple payment break-even is estimated closing costs divided by estimated monthly P&I savings, rounded up to whole months. If the new P&I is not lower, a payment-based break-even does not apply. That formula does not capture lifetime interest or the effect of extending the loan term — use the savings-horizon table for those checkpoints.

Extending the term — for example from 22 years remaining into a new 30-year loan — can lower the monthly P&I while increasing total interest. The calculator shows both views so a lower payment is not mistaken for a lower borrowing cost.

No. Results are principal and interest only unless you separately account for taxes, insurance, HOA dues, and mortgage insurance. Those items can change the total housing payment even when P&I declines.

Yes. Choose the cash-out mode and enter a cash-out amount. The illustrated new loan amount includes the remaining balance, estimated closing costs, and cash-out. The payment may increase even if the rate is lower, because the balance is higher.

No. You enter a new rate assumption. National Mortgage Center does not publish a live advertised rate in this tool. Actual rates, APR, and fees vary by credit, occupancy, property, loan program, and market conditions, and require a Loan Estimate after application.

It is as accurate as the assumptions you enter and the P&I formula. It cannot know your underwriting result, discount points, credits, prepaid items, or escrow. Use it to frame questions, then review official disclosures with a licensed mortgage professional.

You can switch those modes to start from that path, then enter your own rate, term, and cost assumptions. Streamlined programs have additional eligibility rules that this calculator does not underwrite. See the FHA Streamline and VA IRRRL guides for program education.

That can happen if the new rate is not lower, you take cash out, you shorten the term, or costs are financed into the balance. A higher P&I can still be worth reviewing for a shorter payoff or a more predictable rate — compare the horizon table and remaining interest, not only the monthly box.

Enter the term you would actually consider. A 15-year term usually raises the monthly P&I and may reduce remaining interest if you keep the loan. A 30-year term often lowers the monthly P&I and may increase lifetime interest, especially if you already have fewer than 30 years remaining.

There is no universal number. A shorter illustrated break-even is easier to recover if you keep the loan. If you expect to move or pay off the mortgage before that point, estimated costs may outweigh the monthly difference. Compare break-even with your time horizon.