Auto refinance calculator

Compare keeping your current balance with replacing it under new loan terms. Enter the remaining months on your existing loan, then enter the proposed APR, term, and fees to finance. The tool estimates both monthly payments and all future payments from today. A payment reduction and a total cost reduction are different results, so the calculator shows both.

Starting inputs use official educational examples. Zero tax, fees, cash contributions, and extra payments mean those items are excluded until you enter them. Replace these assumptions with your own transaction amounts.

Use the remaining term, not the original term

Start with the balance you owe now and the number of payments still scheduled. Entering the full original term would make the current loan appear to run longer than it actually does. If your payoff quote includes charges that are absent from the statement balance, compare those documents before relying on this model. This calculation assumes the current balance can be repaid with equal monthly payments over the remaining months.

Account for fees once

The fee field is for costs added to the new balance. New principal equals the current balance plus financed refinance fees. If you pay a fee in cash, you can account for it separately when comparing the result with your offer; do not also add the same fee to the financed amount. The calculator excludes cash-paid costs, so the displayed savings need to be reduced by any such costs. Include an existing prepayment charge in financed fees only if the new loan actually finances it.

Read payment savings and total savings together

Monthly reduction is the existing estimated payment minus the proposed payment. Total future savings is the existing remaining payment total minus the new payment total, including interest on financed fees. A negative figure indicates a higher cost under the proposed terms. Changing the term can lower the payment while increasing the total amount repaid. You can compare a proposal with the same remaining term first, then test a different repayment period to see the tradeoff.

Make a comparison you can check

Keep a copy of both loan offers and compare the written amount financed with the value used here. Check whether the APR differs from the note interest rate. This model treats the entered annual rate as the amortization rate, which makes it useful for scenarios but can differ from the contract calculation. The result does not assess eligibility, vehicle restrictions, credit approval, or whether a refinance is available. Use the early payoff tool if your main aim is to reduce interest by paying more each month instead of replacing the loan.

Check early repayment terms

CFPB explains that refinancing requires paying the original loan in full and that an existing prepayment penalty can add a fee. Review your current agreement before comparing offers. A lower APR alone cannot show whether a refinance saves money after all costs and any term extension are included.

Worked example

Official CFPB worked example: a $20,000 loan at 4.75% interest. The published figures are rounded to whole dollars. See the original example. The calculator uses unrounded values internally and displays cents.

How it works

P is the financed principal, r is the monthly rate, n is the number of monthly payments, and M is the regular payment. Each month, interest equals the previous balance multiplied by r. Principal repaid equals the payment minus that interest. The remaining balance falls by the principal repaid. These steps generate the schedule shown by the tool.

This is the standard fixed-payment amortization model described by CFPB auto loan amortization guidance. We use the entered APR as the annual rate for this estimate. APR can include fees; a contract payment based on a separate note interest rate can differ. Use the contract interest rate in the rate field for a closer payment match when it differs from APR. There are no balloon payments, late fees, missed payments, or daily interest adjustments in this model.

Current future cost = current monthly payment x remaining months. New future cost = new monthly payment x new months. New principal = balance + financed fees. Total savings = current future cost - new future cost. These are arithmetic comparisons of the amortized payment totals, not a forecast of qualification.