Auto Loan Calculator
Work out the monthly payment on a car loan, see how much you actually finance once sales tax and fees are rolled in, and find out what the car costs in total by the time it is paid off.
Sales tax is charged on the full vehicle price here. Some states tax only the price after a trade-in, and rates vary by state and county — check your state’s rule.
Formula and calculation
Worked example
A $35,000 car with $5,000 down, a $3,000 trade-in, 6.5% sales tax and $500 of fees, financed at 7.5% over 6 years: the amount financed is $29,775.00 — which includes $2,275.00 of sales tax — the monthly payment is $514.81, and you pay $7,291.54 in interest.
What the amount financed includes
The amount financed is rarely just the price minus your down payment. It is the price minus the down payment and trade-in, plus sales tax on the vehicle and any fees (title, registration, dealer prep) that the dealer rolls into the loan. Financing tax and fees feels painless because no cash changes hands, but you pay interest on them for the life of the loan — $2,000 of tax and fees at 7.5% over 6 years costs about $490 in extra interest. Paying the fees upfront when you can keeps them off the loan entirely.
What the results mean
- Monthly payment
- Your fixed monthly payment on the amount financed. It covers principal and interest only — not insurance, fuel or maintenance.
- Amount financed
- What you actually borrow: the price after your down payment and trade-in, plus sales tax and any fees rolled into the loan.
- Price after down payment and trade-in
- The price left after the down payment and trade-in, before tax and fees are added back. This is the part of the loan that pays for the car itself.
- Sales tax
- The sales tax on the purchase, charged on the full vehicle price in this calculator. In states that tax only the post-trade-in amount, the real figure is lower.
- Total interest
- Interest paid over the whole term if you keep the loan to the end. Longer terms and a bigger amount financed both push this up.
- Total cost
- Everything the car costs you: vehicle price + sales tax + fees + all the interest. Compare it with the sticker price to see what financing adds.
- Payoff date
- The month of your final payment, counted from the first payment date you entered.
Frequently asked questions
How is a car loan payment calculated?
With the amortization formula payment = P × r ÷ (1 − (1+r)^−n) on the amount financed. $30,000 at 6% over 60 months comes to $579.98 a month; the same loan at 7% costs $594.04 — a rate difference worth checking before you sign.
Is sales tax on a car charged on the full price or after the trade-in?
It depends on the state: most charge tax on the full vehicle price, while some charge only on the difference after a trade-in. This calculator taxes the full price, so if your state uses the difference, your tax will be lower — roughly tax% × trade-in, about $195 on a $3,000 trade-in at 6.5%.
How much should I put down on a car?
A common rule of thumb is 20% down, or at least enough to keep the loan from being bigger than the car's value. New cars lose value quickly, so a small down payment on a long loan can leave you owing more than the car is worth if you need to sell early.
Does a longer car loan really cost more?
Yes. Stretching a $30,000 balance from 60 to 72 months at 7% drops the payment from about $594 to $511, but adds roughly $1,180 of interest and keeps you in debt a year longer. Compare total interest in the results, not just the monthly figure.