Calculate your monthly car payment including sales tax, trade-in and down payment, plus total interest over the loan.
Informational only — not financial advice. This calculator provides general estimates for educational purposes and does not account for every factor in your situation. It is not financial, investment, tax, or legal advice. Figures are estimates and may not reflect current rates. Consult a qualified professional before making financial decisions.
An auto loan works on the same amortization math as a mortgage, but with a few car-specific twists: sales tax is added to the amount financed, and a trade-in or down payment reduces it. This calculator rolls it all together to estimate your true monthly payment and the total interest you'll pay.
Sales-tax rules vary by state — many let you tax the price after subtracting the trade-in, which is what this tool assumes. Enter your state's rate to approximate it, and confirm the exact treatment locally.
Stretching a car loan to 72 or 84 months lowers the payment but sharply raises total interest and the risk of being "underwater" (owing more than the car is worth). A shorter term with a slightly higher payment is almost always cheaper overall.