Auto loan calculator

The price on the sticker isn’t the number that hits your budget every month - the loan amount is what’s left after a down payment and trade-in, spread across a rate and a term. This calculator turns those inputs into a monthly payment and the total interest the loan will cost.

Enter the amount actually credited toward the purchase, not the payoff on a trade-in that still has a loan.

How the math works

The amount financed is the vehicle price minus your down payment and trade-in credit. That balance runs through the standard amortization formula M = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1) to produce a level monthly payment, then the calculator multiplies the payment by the number of months to show total interest over the life of the loan. A longer term lowers the monthly payment but stretches out interest - running the same numbers at a shorter term shows the trade-off directly.

How interest on a car loan actually gets calculated each month walks through the mechanics behind this calculator’s output, and how the size of a down payment affects car loan terms explains why the down payment field moves the payment as much as it does. Why new car loans usually have lower rates than used car loans covers what typically drives the rate you’re quoted, and what trade-offs come with choosing a longer car loan term digs into the term-length decision this tool makes visible.

Sources & further reading

This tool is a general educational estimate, not financial advice or a loan offer. Real quotes vary by credit, lender, fees, and taxes. See our disclaimer.