Estimate your monthly car payment on a new or used vehicle. This free car loan calculator factors in your down payment, trade-in, sales tax and interest rate to show your monthly payment, total interest and the true cost of financing the car.
Results update automatically as you type. Estimates only — confirm exact figures with your lender or dealer.
How the Car Loan Calculator Works
This car loan calculator works out what you’ll pay each month to finance a new or used car by folding your down payment, trade-in and sales tax into the amount financed, then applying your loan’s interest rate over its term.
Formula: Sales tax = (Car price − Trade-in value) × Tax rate. Amount financed L = Car price + Sales tax − Down payment − Trade-in value. Monthly payment M = L × [r(1+r)^n] / [(1+r)^n − 1]
- M — your fixed monthly car payment
- L — the total amount financed (what you actually borrow)
- r — monthly interest rate, equal to the APR divided by 12
- n — number of monthly payments over the loan term
- Sales tax rate — applied to the car’s price minus your trade-in credit in most states
Example Scenarios
| Car Price | Down Payment | Trade-in | Sales Tax | APR | Term | Monthly Payment |
|---|---|---|---|---|---|---|
| $18,000 | $1,500 | $0 | 6% | 8% | 48 mo | $429 |
| $28,000 | $4,000 | $6,000 | 6% | 7.5% | 60 mo | $387 |
| $35,000 | $5,000 | $0 | 0% | 6% | 72 mo | $497 |
| $45,000 | $9,000 | $0 | 0% | 6.9% | 60 mo | $711 |
| $22,000 | $2,200 | $3,000 | 5% | 9% | 36 mo | $565 |
Car Loan Calculator FAQ
Is a car loan calculator accurate for used cars, not just new ones?
Yes — the math (loan amount, interest rate and term) works the same for used and new vehicles. The main difference is that used-car loans often carry higher interest rates than new-car loans, and some lenders cap the term based on the vehicle’s age, so use the rate your lender actually quotes.What happens if I still owe money on my trade-in?
If your trade-in is worth less than what you owe on it, that negative equity gets added to the amount you’re financing rather than subtracted, increasing your loan balance and monthly payment. This calculator assumes a trade-in with no outstanding loan; adjust the trade-in figure to reflect your actual payoff.Does sales tax get added to the loan or paid separately?
Most buyers finance the sales tax along with the vehicle price rather than paying it out of pocket, so it’s added to the loan amount here. Some states also treat trade-in tax credit differently, so the exact tax treatment depends on where you register the car.How much car can I afford based on a monthly payment I can handle?
Work backward from the payment: pick a target monthly amount, then adjust the price, down payment or term until the calculator’s output matches. Lenders also look at your total monthly debt relative to income, so a payment that fits your budget should still leave room for other expenses.Why do two lenders quote different monthly payments for the same car?
The interest rate is usually the biggest driver — even a one- or two-point difference in APR changes the payment noticeably over a 5- or 6-year term. Fees, add-ons and whether tax is rolled into the loan can also shift the financed amount and therefore the payment.Does refinancing a car loan change how the payment is calculated?
Refinancing simply replaces your current loan with a new one — plug the new loan balance (your current payoff amount), the new interest rate and the new term into this calculator the same way you would for a purchase loan to see the new monthly payment.Related Calculators
Shopping specifically for a new vehicle? The auto loan calculator uses the same math for new-car financing. Once you’ve settled on a payment, the cost per mile calculator can help you weigh total ownership costs, and the debt-to-income ratio calculator shows how the payment fits into your broader budget.