Car Refinance Calculator
What refinancing your car loan saves each month and in total, after fees.
Good to know. A lower rate saves money. A longer term mostly moves it: smaller payments, for more months.
Not financial advice. Uses only the numbers and rates you enter — no live data.
How it works
In plain words
Work out the payment that clears what you owe over the months left at today’s rate, and the payment on a new loan for the same balance plus fees. The total saving compares everything still to be paid on each.
The formula
current = payment(balance, rate, months left) new = payment(balance + fees, new rate, new term) total saved = current × months left − new × new term
Worked example
Owing 18,000 at 9% with 48 months left, the payment is 447.93. Refinanced at 6% over the same 48 months it is 422.73: 25.20 less a month, and 1,209.61 less in total.
Sources
- Brealey, Myers and Allen, Principles of Corporate Finance, chapter 2 The standard formulas for loan payments, compounding and present value, the same as a spreadsheet’s PMT and FV.
Sources checked October 3, 2026. 4 automated tests check its answers on every change.
About the car refinance calculator
Refinancing replaces your car loan with a new one, ideally at a lower rate. It makes sense when rates have fallen, when your credit score has improved since you bought the car, or when the dealer’s financing was expensive to begin with.
Compare like with like. Keeping the same number of months left shows the pure saving from the lower rate. Stretching the new loan over more months lowers the payment further, but the total saved shrinks or turns into a loss, because you pay interest for longer.
Count the costs: some lenders charge an application or title transfer fee, and a few old loans charge for paying off early. Here, fees are added to the new loan, as is common.
Cars lose value quickly, and lenders may not refinance a car worth less than what you owe, or one that is old or high-mileage. The car loan calculator shows a loan’s full schedule, and the loan comparison calculator weighs two offers against each other.
Questions people ask
Is it worth refinancing a car loan?
Usually when you can cut the rate by a point or more without extending the term much, and fees are small.
Does refinancing a car hurt my credit?
A new application causes a small, temporary dip. Shopping for rates within a short window counts as one enquiry for most scores.
Should I extend the term when I refinance?
Only if you need the lower payment. A longer term usually means paying more interest in total.