Auto Loan Calculator
This free auto loan calculator estimates your monthly car payment from the vehicle price, down payment, trade-in value, APR, and loan term — and shows how much of the total cost is principal versus interest, so you can see the true price of the loan before you sign.
Enter your numbers
Your results
Loan summary
| Item | Amount |
|---|
Principal vs interest
Estimate only — not lending advice. Actual loan offers vary by lender, credit history, fees, and taxes. Taxes and dealer fees are not included.
How to use this calculator
Start with the vehicle price, then subtract what you're paying up front: your down payment and any trade-in value. What's left is the amount you'd actually finance — that's the number the interest is calculated on.
Enter the APR you've been quoted (or the rate you expect) and pick a loan term — 36, 48, 60, or 72 months are the most common, or type any term from 6 to 96 months. Results update instantly as you change any input.
The donut chart shows how much of your total payments goes to the principal versus interest. Try a longer term or a smaller down payment to see how quickly the interest slice grows.
How it works
First the calculator finds the amount financed: vehicle price − down payment − trade-in. Then it applies the standard loan amortization formula to spread that balance into equal monthly payments:
M = L × r × (1+r)n / ((1+r)n − 1), where M is the monthly payment, L is the amount financed, r is the monthly interest rate (APR ÷ 1200), and n is the number of months. With a 0% APR, the payment is simply L ÷ n.
Total paid is the monthly payment × number of months, and total interest is total paid − amount financed.
Assumptions: the APR stays fixed for the whole term; payments are equal and made monthly; taxes, dealer fees, registration, and insurance are not included (they vary by state and lender). All figures are estimates for planning — not lending advice and not a loan offer.
Frequently asked questions
How is a monthly car payment calculated?
Lenders start with the amount financed (vehicle price minus down payment and trade-in), then apply the standard loan amortization formula: M = L × r × (1+r)n / ((1+r)n − 1), where L is the amount financed, r is the monthly rate (APR ÷ 1200), and n is the number of months. With a 0% APR, the payment is simply the amount financed divided by the number of months.
How much should I put down on a car?
A widely cited rule of thumb is to put at least 20% down on a car. A larger down payment shrinks the amount you finance, which lowers your monthly payment and the total interest you pay over the life of the loan. It isn't a requirement — lenders will finance with less down — but less down means more interest and a longer stretch where you might owe more than the car is worth.
What's the difference between APR and interest rate?
The interest rate is the cost of borrowing the principal alone. The APR (annual percentage rate) folds in certain lender fees to reflect the loan's true yearly cost, so it's usually the better number to compare when shopping between lenders. This calculator uses the APR you enter as the basis for the monthly rate.
Will paying extra each month save interest?
Yes, conceptually: extra payments go toward the principal, which shrinks the balance that interest accrues on — so you pay less interest overall and finish the loan sooner. Check with your lender first that extra payments are applied to principal and that there's no prepayment penalty. This calculator models fixed scheduled payments only, not extra payments.
Is this quote guaranteed?
No. The numbers on this page are estimates for planning only — not lending advice and not a loan offer. Actual offers from lenders will vary based on your credit history, the lender's fees, taxes, and the final vehicle price.