View full amortization schedule ▾
| Year | Principal paid | Interest paid | Balance |
|---|
How this auto loan calculator works
Enter the vehicle price, what you're putting down, your trade-in situation, your state's sales tax rate, the loan term and the APR you've been quoted. The calculator works out the amount you'll actually finance and the fixed monthly car payment that repays it exactly on schedule. Every figure — payment, total interest, total cost and the amortization schedule — updates live as you type.
How the amount financed is worked out
The amount financed is rarely the sticker price. It's the vehicle price, plus sales tax, minus your down payment, minus your trade-in equity:
- Vehicle price — the agreed sale price before tax.
- Sales tax — charged on the price less your trade-in value in most US states (the trade-in tax credit), then financed along with the car unless you pay it at signing.
- Down payment — cash you put in up front, which comes straight off the balance.
- Trade-in equity — your trade-in's value minus what you still owe on it. Positive equity acts like extra down payment; negative equity gets added to the new loan.
Whatever is left is the balance your monthly car payment has to repay, with interest, over the term.
How your monthly car payment is calculated
This calculator uses the standard fixed-rate amortization formula. Interest is charged each month on the balance that remains, so early payments go mostly to interest and later payments go mostly to principal. The amortization schedule above shows that shift year by year, along with the balance still owing at the end of each year — useful for judging when you'd break even if you wanted to sell or trade the car early.
Trade-ins and negative equity
If you owe more on your current car than a dealer will give you for it, you have negative equity. Rolling it into the new loan is normal and usually the only practical option, but it means you start the new loan already owing more than the new car is worth — and you pay interest on the old car's shortfall for the whole term. Enter both your trade-in value and the amount owed above to see exactly what that does to your payment.
Choosing a loan term
Term is the biggest lever on the monthly number and one of the biggest on total cost. A shorter term raises the payment but cuts total interest sharply and gets you into positive equity faster. 36 to 60 months is the usual sweet spot. 72 and 84 month loans make an expensive car look affordable, but you'll pay noticeably more interest and stay underwater for years. Switch between the term buttons above to see the trade-off in real numbers.
APR, credit and dealer financing
The APR bundles the interest rate with certain lender fees, so it's the number to compare offers on. Auto loan rates vary widely by credit profile, loan term, and whether the car is new or used — used-car rates are typically a couple of points higher. Getting pre-approved by your own bank or credit union before you walk in gives you a rate to beat and turns the dealership conversation into a price negotiation rather than a payment negotiation.
Ways to lower your total cost
- Negotiate the vehicle price, not the monthly payment — a longer term can hide a worse deal.
- Put more down; every dollar reduces the financed balance and the interest on it.
- Choose the shortest term you can comfortably afford.
- Get pre-approved elsewhere before accepting dealer financing.
- Clear negative equity separately if you can, rather than rolling it forward.
- Remember the running costs — insurance, fuel, tax and maintenance aren't in this payment.
Frequently asked questions
How is my monthly car payment calculated?
Your payment is the fixed monthly amount that repays the amount financed, with interest, over the term you choose. The amount financed is the vehicle price plus sales tax, minus your down payment and any trade-in equity. The calculator then applies the standard fixed-rate amortization formula to that balance at your APR.
How does a trade-in affect my auto loan?
Your trade-in equity is the vehicle's value minus anything you still owe on it. Positive equity works like extra down payment and reduces the amount financed. If you owe more than the car is worth, that negative equity is usually rolled into the new loan, which increases the amount financed and your payment.
Is sales tax included in a car loan?
In most cases yes — sales tax is added to the price and financed along with it unless you pay it separately at signing. This calculator adds sales tax to the price and applies the trade-in tax credit used by most US states, where tax is charged on the price minus your trade-in value. A few states tax the full price, so check your state's rule.
What is a good auto loan term?
Shorter terms mean a higher monthly payment but far less total interest, and they keep you from owing more than the car is worth. 36 to 60 months is the usual sweet spot. 72 and 84 month loans lower the payment but cost significantly more overall and leave you in negative equity for longer.
Does this include insurance, registration and fees?
No. It models the loan itself — price, tax, down payment, trade-in, term and APR. Dealer documentation fees, title and registration, extended warranties and insurance are not included. If those are being financed, add them to the vehicle price to see their true effect on your payment.
Are my numbers saved or sent anywhere?
No. Nothing you enter leaves your device. The math runs entirely in your browser, and the optional share link only stores the numbers you choose to share inside the link itself.