Use this auto loan calculator to quickly determine an estimate of your monthly payment for the used or new car you're looking to buy. Provide as input the following: vehicle price, down payment, trade-in value, state sales tax, interest rate assumption, and the auto loan terms in number of months. The down payment should be the cash payment you can afford to put down. The trade-in value should be the trade-in value of your old vehicle less any outstanding loan balance. The auto loan terms are typically 36, 48, 60 or 72 months; the longer the loan terms, the less the monthly payment would be but keep in mind you would end up paying more interest over the life of the auto loan. Once you have entered the required information, click on the "Calculate" button and the auto loan calculator will show you the results in terms of an estimate of the total loan amount you will need to get, the monthly payment, and the total amount (principal plus interest) that you would pay over the life of the auto loan.