Free Auto Loan Calculator
Enter the vehicle price, your down payment and trade-in value, the APR, and the loan term to see your monthly payment, total interest, and the true cost of the car.
This free auto loan calculator subtracts your down payment and trade-in from the vehicle price to get the financed amount, then applies the standard amortization formula. For example, financing $30,000 at 7 percent APR for 60 months gives a monthly payment of about $594, with roughly $5,640 in total interest.
Estimates only. This tool covers the loan itself; it does not include sales tax, title and registration fees, dealer add-ons, or insurance. Not financial advice.
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How auto loan math works
An auto loan uses the same amortization formula as a mortgage: monthly payment = financed amount times the monthly rate, divided by one minus (1 + monthly rate) raised to the negative number of payments. The financed amount is the vehicle price minus down payment minus trade-in value, plus anything rolled in like taxes or fees.
Take a $35,000 car with $5,000 down, no trade-in, at 7 percent APR for 60 months. The financed amount is $30,000. The monthly rate is 0.07 divided by 12, about 0.005833, over 60 payments. The monthly payment comes out to about $594. Total payments are about $35,640, so total interest is roughly $5,640.
Term length is the biggest lever after price. Stretching that same loan to 72 months drops the payment to about $511 but raises total interest to roughly $6,790. At 84 months the payment is about $453 while interest climbs to roughly $8,050. Longer terms also keep you owing more than the car is worth for longer, since cars depreciate fastest in the first years.
APR matters more than most buyers think. On that $30,000, 60-month loan, a 4 percent APR gives a payment of about $552 and total interest of about $3,140, while a 10 percent APR gives about $637 a month and $8,220 in interest. Three points of rate difference costs over $5,000 on this loan, which is why lining up financing before visiting the dealer pays.
Watch what gets rolled into the financed amount. Sales tax, extended warranties, and negative equity from a previous car (owing more than the trade-in covers) all inflate the loan and the interest. A $3,000 warranty rolled into a 7 percent, 60-month loan costs about $3,530 by the time it is paid off.
Auto loan questions
What is a good APR for a car loan?
It depends on your credit tier and whether the car is new or used. Borrowers with excellent credit typically see the lowest advertised rates, often several points below what subprime borrowers are offered. Shorter terms usually price lower than longer ones. Get pre-approved from a bank or credit union before dealer shopping so you have a baseline to beat.
How long should a car loan be?
Shorter is cheaper in total interest: 36 to 48 months minimizes interest paid, 60 months is the common middle ground, and 72 to 84 months lowers the monthly payment but piles on interest. Long terms are risky because cars depreciate fastest early, so you can owe more than the car is worth for years. If you need 84 months to afford the payment, the car is probably too expensive.
Does my trade-in reduce my car loan?
Yes, dollar for dollar, if you own the trade-in outright: a $35,000 car with a $8,000 trade-in and no payoff finances $27,000 before any down payment. If you still owe on the trade-in, only the equity (its value minus your payoff amount) reduces the new loan. If you owe more than it is worth, that negative equity gets added to the new loan.
Should I put money down on a car?
Yes, if you can. Around 10 to 20 percent down on a new car (about 10 percent on used) shrinks the monthly payment, cuts total interest, and provides a buffer against depreciation so you do not end up owing more than the car is worth. It also signals to lenders that you are a lower risk, which can help the rate.