Auto Loan Payment Calculator
Enter the vehicle price, your down payment and trade-in, the sales tax, and your rate and term. You'll get the monthly payment, total interest, and what the car really costs by the time it's paid off.
The negotiated price before tax and fees
What the dealer credits for your current car
Combined state and local rate
Your loan's annual rate
Monthly payment
—
Total interest
—
Total cost of the car
—
The term-length trap
Stretching a loan from 60 to 84 months can cut the payment by a couple hundred dollars, which is exactly why dealers offer it. The cost shows up twice. First, more months of interest on a balance that falls slowly. Second, negative equity: a car loan is secured debt, and the asset securing it loses value fastest in the first years, right when a long loan pays principal slowest. Owe $24,000 on a car worth $19,000 and you can't sell it, can't trade it without rolling the gap into the next loan, and a totaled-car insurance check won't clear the balance. The 48-month comparison line above exists to make that trade visible before you sign.
Taxes and fees ride along
The sticker price is not the amount financed. Sales tax, title, registration, and dealer fees typically roll into the loan, so a $32,000 car at 7% tax starts as a $34,240 obligation before the down payment does its work. Financing the tax means paying interest on the tax for five or six years. It's a small leak, not a scandal, but it's one more reason the honest question isn't "what's the payment" but "what does this car cost in total", which is the third number this calculator reports.
Buy the car, not the payment
Dealers negotiate in monthly payments because payments are easy to stretch. The stronger position is to fix your budget first: decide the all-in monthly cost you can carry (payment, insurance, fuel, maintenance) with the car affordability calculator, check what the payment does to your debt-to-income ratio, and only then shop inside that number. A car payment is one of the classic vehicles for lifestyle creep: it arrives with every raise and never leaves. Seeing the loan balance, the payment, and the rest of your money in one place is what Stoia is built for, so the car stays a purchase instead of becoming a lifestyle.
Frequently asked questions
How is a car payment calculated?
Standard amortization: the amount financed, the monthly interest rate, and the number of months determine a fixed payment that pays interest first and principal second. Financing $28,000 at 7% APR over 60 months comes to about $554 a month, with roughly $5,270 of that being interest.
Does the sales tax get financed too?
Usually, yes. Unless you pay tax and fees in cash at signing, they roll into the loan, which means you pay interest on the tax for the life of the loan. On a $32,000 car at 7% tax, that's about $2,240 added to the amount financed before you've driven anywhere.
Are 72 and 84 month car loans a bad idea?
They buy a lower payment with more total interest and more years spent owing more than the car is worth. Cars depreciate fastest early, while long loans pay principal slowest early, so the gap between loan balance and car value can stay negative for years. If you need 84 months to afford the payment, the car is usually too expensive.
How much should I put down on a car?
A common guideline is about 20% on a new car and 10% on a used one. The point is to start with equity: a real down payment absorbs the first-year depreciation so you're never underwater, and it shrinks both the payment and the total interest.
Does a trade-in reduce the sales tax?
In many states, yes: tax applies to the price minus the trade-in value. Rules vary by state, and this calculator taxes the full vehicle price, so in trade-in-credit states your real numbers will come out slightly better than shown here.
Does this calculator save my numbers?
No. Everything runs in your browser and disappears when you leave. Nothing is uploaded or stored.
Want this to update itself?
Stoia connects your real accounts and keeps the full picture current: net worth, budgets, and goals. Launching in 2026.