Auto Loan Calculator
Calculate your monthly car payment with sales tax, down payment and trade-in — plus the total interest and total cost of the loan.
About this calculator
This free auto loan calculator estimates your monthly car payment and the true cost of financing, accounting for sales tax, your down payment and any trade-in — the numbers a dealer's quote often glosses over.
How it works
Sales tax is applied to the price minus your trade-in (the rule in most states). The amount financed is price + sales tax − down payment − trade-in, and the monthly payment uses the standard amortized-loan formula at your APR over the term in months.
Worked example
A $35,000 car with $5,000 down, no trade-in, 6% sales tax and a 60-month loan at 7% APR finances about $32,100 for a monthly payment near $636, with roughly $6,000 of total interest.
Buying a home instead? Use the mortgage calculator, or compare any loan with the loan calculator.
Why use this auto loan calculator
Tax and trade-in built in
Sales tax is applied to the price minus your trade-in (the rule in most states), so the amount financed and payment are realistic.
See the true cost
Beyond the monthly payment, it shows total interest and total cost — the numbers a dealer quote often leaves out.
Compare loan terms
Flip between 48, 60 and 72 months to see how a longer term lowers the payment but raises what you pay overall.
Common use cases
- Work out an affordable monthly payment before visiting the dealer
- Check how much a trade-in lowers your payment and tax
- Compare financing offers at different APRs
- Decide between a shorter term and a smaller payment
Frequently asked questions
The amount financed is the vehicle price plus sales tax, minus your down payment and trade-in. The monthly payment then uses the amortized-loan formula on that amount at your APR over the loan term in months.
In most US states, sales tax is charged on the price after subtracting the trade-in value, which lowers the tax you pay. This calculator applies tax to the price minus trade-in. A few states tax the full price — check your state's rule.
Yes, but you pay more total interest. A 72-month loan has a smaller monthly payment than a 48-month loan at the same rate, yet costs more overall because interest accrues for longer.
A larger down payment lowers the amount financed, your monthly payment and total interest. Many buyers aim for 10–20% down to avoid being 'upside down' (owing more than the car is worth).
Yes. Everything is calculated in your browser and nothing you enter is uploaded or saved.
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