Mortgage Refinance Calculator

About this calculator

This calculator compares your existing mortgage to a potential refinance by computing the monthly payment on both loans using the standard amortization formula, then subtracting to find your monthly savings. Total interest for each scenario is calculated as (monthly payment × number of payments) minus the loan balance. The break-even point divides your closing costs by the monthly savings to show how many months it takes to recoup the upfront refinance costs — if you plan to stay in the home longer than that, refinancing is likely worth it.

Field explanations

Current loan balance

The principal amount still owed on your existing mortgage. Check your most recent statement for the current payoff amount.

Current interest rate

The annual interest rate on your existing loan. Found on your mortgage statement or closing documents.

Remaining years on loan

How many years are left on your current mortgage. For example, if you took a 30-year loan 5 years ago, enter 25.

New interest rate

The rate you expect to qualify for on the refinanced loan. Check with lenders for current quotes — even a small rate drop can produce significant lifetime savings.

New loan term

The term length for the new loan in years. A shorter term (e.g. 15-year) means higher payments but less total interest; a longer term lowers the monthly payment but can increase lifetime interest paid.

Closing costs

Upfront fees required to complete the refinance — typically 2–5% of the loan amount and may include origination fees, appraisal, title insurance, and prepaid items. Enter 0 for a no-cost refinance.