Auto Refinance Calculator
Find out whether refinancing your car loan will lower your monthly payment and your total interest, after fees.
When does refinancing a car loan pay off?
Refinancing replaces your current auto loan with a new one — ideally at a lower APR. It tends to make sense when your credit score has improved since you bought the car, when market rates have dropped, or when you took dealer financing without shopping around. This calculator compares the total remaining cost of your current loan (every payment still to come) with the total cost of the new loan plus fees.
Lower payment isn't always a better deal
Stretching the new loan over more months can cut your monthly payment even at the same rate — but you'll usually pay more interest overall. Keep the new term equal to or shorter than your remaining months if your goal is to save money, and compare the net lifetime savings figure, not just the payment.
The formulas
Both payments use the standard amortization formula: P × r(1+r)n ÷ [(1+r)n − 1]. Remaining cost of the current loan = current payment × months remaining. Cost of the new loan = new payment × new term, plus fees if paid upfront. Break-even = upfront fees ÷ monthly savings.
Not sure what rate to expect? See what counts as a good car loan APR right now.
Frequently asked questions
Does refinancing a car hurt my credit?
Applying causes a hard inquiry and a new account, which can dip your score slightly for a short time. Rate shopping within a short window is generally treated as a single inquiry by common scoring models.
Can I refinance if I owe more than the car is worth?
It's harder. Many lenders cap the loan-to-value ratio, so being upside down may mean paying down the balance first or accepting a higher rate.
Are there prepayment penalties on auto loans?
Most auto loans don't have them, but check your contract. Any penalty should be added to the fees field.
How soon can I refinance after buying?
Many lenders require that the title has transferred and a few payments have been made, often 60–90 days after purchase.