Auto Loan Calculator
Enter the vehicle price, your down payment, the trade-in value, the sales tax rate, the interest rate and the term in months. Add any fees, either rolled into the loan or paid in cash. The calculator returns the monthly payment, the amount you finance, the total interest, the total of all payments, the cash due at signing and the total cost.
How to use the Auto Loan Calculator
- Enter your numbers in the Auto Loan Calculator above.
- Press the Calculate button to see the result.
- To try other numbers, change any value and press the button again.
The auto loan payment formula
M = P · r(1 + r)^n / ((1 + r)^n − 1), where P = price + sales tax − down payment − trade-in + fees on the loan
The calculator takes the sales tax rate times the full vehicle price and adds that tax to the price. It then subtracts the down payment and the trade-in to get P, the amount you finance. r is the annual interest rate divided by 12, n is the term in months, and M is the fixed monthly payment, rounded to the cent. Each month the interest is rounded to the cent too, so the last payment pays off what is left and can differ from M. The totals add up the payments you actually make.
Worked example
Sales tax of 7% on a $32,000 car is $2,240. Take off a $4,000 trade-in and $3,000 down and you finance P = $27,240. At 7.5% over 60 months the payment is M = $545.83 and the last payment is $546.11. You pay $32,750.08 in total, of which $5,510.08 is interest.
Frequently asked questions
How do fees change the car payment?
Fees added to the loan raise the amount financed, so you pay interest on them too. Fees paid in cash leave the loan alone and add to the cash at signing. On the $27,240 example loan at 7.5% over 60 months, $800 of fees on the loan and $300 in cash make it $28,040 financed at $561.86 a month, with $3,300 at signing. The total cost counts that cash, the $4,000 trade-in and every payment, which comes to $41,011.88. The calculator does not add sales tax to a fee, and it uses the fee amounts you type, so take them from the dealer's offer.
Does the calculator finance the sales tax?
Yes. It adds the sales tax to the loan, which raises both the payment and the interest. It taxes the full vehicle price, before the down payment and trade-in come off. If you will pay the tax in cash at signing, enter 0 as the sales tax rate and the loan covers the price alone.
How does a trade-in affect my loan?
The calculator subtracts the trade-in value from the amount you finance, dollar for dollar. If you still owe money on the car you trade in, enter its value minus that payoff. When you owe more than the car is worth, the number is negative and the shortfall goes onto the new loan. In the example, a trade-in of −$2,000 instead of $4,000 raises the loan to $33,240 and the payment to $666.06.
What auto loan term is best?
A shorter term costs more each month and less in total. The example loan of $27,240 at 7.5% costs $658.63 a month and $4,374.48 in interest over 48 months. Stretch it to 72 months and the payment falls to $470.98 while the interest climbs to $6,670.78.
Does my credit score affect the rate?
Yes. Lenders set auto loan rates partly by credit score, so enter the rate from your own loan offer. The rate moves the result a lot. At 5% the example loan costs $514.05 a month and $3,603.16 in interest. At 10% it costs $578.77 a month and $7,486.16 in interest, more than twice as much.