Auto loan refinance calculator
Should you refinance? Side-by-side comparison of your current loan vs a new refinance offer, with monthly savings, lifetime savings, and break-even period including fees.
When does refinancing make sense?
Refinancing an auto loan replaces your current loan with a new one — typically to lower the APR. The decision comes down to three numbers: monthly payment difference, lifetime interest difference, and the break-even period including fees.
Rule of thumb: if your new APR is at least 1.5-2.0 percentage points lower than your current APR AND you'll keep the vehicle past the break-even point, refinancing usually saves money. If you're planning to sell or trade-in within the break-even period, the fees won't pay off.
Watch the term carefully
A common refinance trap: lengthening the loan term. If you have 36 months left at 9% APR and refinance to a 60-month loan at 6%, your monthly payment drops dramatically — but the total interest paid can go UP because you're paying interest for longer. The calculator above strips this out by showing total lifetime interest, not just monthly savings. Always check total dollars, not just the payment.
For deeper context on refinance timing and when to skip it, see our auto loan refinance guide. Note: refinance lenders typically require the vehicle to be under 10 years old, with less than ~125,000 miles, and an outstanding balance over $3,000-$5,000. They'll also check your credit score; if it's below 660, see bad credit auto loans for sub-prime refinance considerations.
This calculator does not include sales tax (refinancing your loan, not buying a new car, doesn't trigger sales tax) but does account for typical refinance closing fees ($50-$200 title transfer + lender origination + any prepayment penalty on the existing loan). For purchase-related taxes, see our used car sales tax calculator.