How to use this calculator
- Current loan: your payoff balance, current APR and the number of months left. The calculator works out your current payment from these.
- New loan: the APR and term you’ve been offered.
- Refinance fees: lender fees plus any title transfer or registration fees your state charges, and whether you’ll pay them in cash or add them to the new loan.
You get the change in your monthly payment, the break-even month, the total interest saved, your net savings after fees, a chart of how the savings build up, and a side-by-side table of both loans.
How the numbers are worked out
Both loans use the standard payment formula, where r is the APR ÷ 12 and n is the number of months:
Then each month, the calculator measures how far ahead you are:
Counting the balances matters. A shorter new loan has higher payments but pays the balance down faster, and fees added to the loan raise the new balance. The break-even month is the first month this figure reaches zero or more: the point where, if you sold the car and paid off the loan, you’d be no worse off for having refinanced.
Worked example
You owe $22,000 at 10% APR with 48 months left. A lender offers 6.5% for 48 months, with $300 of fees paid in cash.
- Current payment: $557.98 a month, with $4,783 of interest still to pay
- New payment: $521.73 a month, with $3,043 of interest
- Monthly savings: $36.25
- Total interest saved: $1,740
- Net savings after the $300 of fees: $1,440
- Break-even: month 5
Fees are recovered quickly because the lower rate also pays the balance down faster from the first month.
How the new rate changes the result
Same $22,000 balance, 48 months on both loans, $300 of fees paid in cash:
| New APR | New payment | Monthly savings | Interest saved | Net after fees | Break-even |
|---|---|---|---|---|---|
| 5.5% | $511.64 | $46.34 | $2,224 | $1,924 | Month 4 |
| 6.5% | $521.73 | $36.25 | $1,740 | $1,440 | Month 5 |
| 7.5% | $531.94 | $26.04 | $1,250 | $950 | Month 7 |
| 8.5% | $542.26 | $15.72 | $754 | $454 | Month 12 |
| 9.5% | $552.71 | $5.27 | $253 | −$47 | Never |
A half-point cut on a short loan often isn’t enough to cover fees.
When a longer term costs you more
At 6.5%, here is what each new term does:
| New term | New payment | Total interest | Net savings after fees |
|---|---|---|---|
| 36 months | $674.28 | $2,274 | $2,209 |
| 48 months | $521.73 | $3,043 | $1,440 |
| 60 months | $430.46 | $3,827 | $656 |
| 72 months | $369.82 | $4,627 | −$144 |
The 72-month loan has the lowest payment, $188.16 less than today, but after fees it costs $144 more than keeping your current loan. The calculator warns you when a longer term means more interest overall. The CFPB makes the same point about car loans in general: a longer term means smaller payments, but more interest over the life of the loan, and a higher chance of owing more than the car is worth.
If you need the lower payment now, one middle path is to refinance to the longer term and pay extra when you can, as long as the new loan has no prepayment penalty.
Tips before you refinance
- Shop the APR, not the payment. Compare offers with the same term so the rates are directly comparable.
- Ask for the exact payoff amount. It includes interest up to the payoff date, so it’s usually a little more than the balance on your last statement.
- Count every fee. Some states charge to re-title the car or record the new lien, and some lenders charge an origination fee.
- Check your equity. If you owe more than the car is worth, refinancing may be harder.
For a new purchase, use the auto loan calculator. The debt payoff calculator helps if you’re juggling several debts, and the mortgage refinance calculator does the same job for a home loan.
Assumptions and limitations
Both loans are fixed-rate, simple-interest installment loans with level monthly payments, interest at APR ÷ 12 and payments rounded to the cent. The current payment is calculated from your balance, rate and months left, so it may differ by a few cents from your statement. The calculator doesn’t model prepayment penalties, add-on products such as GAP coverage moving to the new loan, or any change in your credit score.
Sources
- Consumer Financial Protection Bureau, How do I compare auto loan offers?
This calculator gives estimates for general information. Your lender’s disclosures show the exact payment, APR and fees.
Frequently asked questions
When does it make sense to refinance a car loan?
When the new rate is low enough that the interest you save is more than the fees, and you keep the term about the same. In our example, refinancing $22,000 with 48 months left from 10% to 6.5% saves $36.25 a month and $1,740 in interest, or $1,440 after $300 of fees. If the new rate were 9.5%, the fees would wipe out the savings.
How do I calculate the break-even point on an auto refinance?
The quick version is fees divided by monthly savings. This calculator goes a step further. Each month, it adds up the payments you've saved, subtracts the fees, and adds the difference between what you'd still owe on each loan. The break-even month is the first month that total turns positive. Our example breaks even in month 5.
Can refinancing a car loan cost more even with a lower rate?
Yes, if the new loan is longer. Stretching our example from 48 to 72 months drops the payment by $188.16, but saves only $156 in interest, and after $300 of fees you'd pay $144 more in total. The lower payment comes mostly from spreading the debt over more months.
Should I add the refinance fees to the new loan?
Adding them keeps cash in your pocket but means you pay interest on them. In our example, rolling $300 of fees into the loan raises the new payment from $521.73 to $528.84 and trims the net savings from $1,440 to $1,398.
Does a shorter refinance term save more?
Usually, as long as you can afford the higher payment. Refinancing our example into 36 months at 6.5% raises the payment to $674.28 but saves $2,509 in interest, about $769 more than keeping 48 months.
What should I check before refinancing my car?
Get the payoff amount from your current lender and check your contract for any prepayment penalty. Compare the APR, term and fees of each offer, not just the monthly payment. If you owe more than the car is worth, some lenders may not refinance it, or may charge a higher rate.
Updated November 2026. Results are estimates for educational purposes and depend on the inputs you provide.