Auto Loan Refinance Savings Calculator
Compare your current car loan with a refinance offer: new payment, monthly change, interest saved, net savings after fees, break-even month and a side-by-side term comparison.
How it works
Payment = P·r ÷ (1 − (1 + r)⁻ⁿ) for each loan (r = APR ÷ 12) · New loan = balance + cash out + financed fees · Interest = payment × months − loan · Net savings = current interest − new interest − all fees · Break-even = upfront fees ÷ monthly saving
Refinancing replaces your existing loan with a new one for the payoff balance, ideally at a lower rate. The calculator first rebuilds your current loan, from the months remaining or from your monthly payment, and adds up the interest you would still pay. It then prices the new loan — the balance plus any cash out and any fees you roll in — and totals its interest. Net savings are the current interest minus the new interest minus every refinance cost (fees, origination and any prepayment penalty), which is the clearest test of whether the deal pays. When you pay fees upfront and the payment falls, the break-even month shows how long it takes for the lower payments to repay those fees. Watch the term: stretching it lowers the payment but can raise total interest, so the side-by-side table and the term comparison show payment, interest and net savings for each choice.
Worked example
A $22,000 balance at 9% with 48 months left costs $547.47 a month and $4,278.60 in remaining interest. Refinancing to 5.5% for 48 months drops the payment to $511.64 (−$35.83) and interest to $2,558.84, saving $1,719.77. With $200 of title and lender fees paid upfront, net savings fall to $1,519.77, and $200 ÷ $35.83 means the fees are recovered after 6 months of lower payments. Stretching the new loan to 72 months cuts the payment to $359.43 but raises interest to $3,879.21, so the saving shrinks to $399.39 before fees.
Sources: CFPB — Can I prepay my loan at any time without penalty?
Frequently asked questions
When is refinancing a car worth it?
Typically when rates have fallen or your credit has improved since you took the loan, and you have meaningful time and balance left. Look at the net savings figure: it subtracts every fee from the interest saved, so a positive number means the refinance pays for itself.
What is the break-even point?
If you pay fees upfront, it is the number of months of lower payments needed to earn those fees back: fees ÷ monthly saving. If you plan to sell the car or pay off the loan before then, the refinance may not be worth it.
Does extending the term save money?
It lowers the monthly payment but usually increases total interest, because you borrow for longer. The term comparison table shows the payment, interest and net savings for 24 to 84 months at the new rate, so you can see the real trade-off.
I only know my monthly payment, not the months left. Can I still use it?
Yes. Choose “Monthly payment” for the current loan and enter the payment with your balance and APR. The calculator works out how many payments remain and the interest still to come.
Should I roll the fees into the new loan or take cash out?
Rolling fees in avoids paying cash now, but you pay interest on them. Cash out adds to the balance and is repaid with interest. Both are counted in the new loan’s totals, so the net savings stay a fair comparison.
Does refinancing hurt my credit?
The lender’s hard inquiry may lower your score a few points for a while, and opening a new account lowers your average account age. These effects are generally small and short-lived compared with the interest you can save.
Related calculators
Educational estimate — real figures vary by vehicle, lender, dealer and local rules.