Calculate your monthly car payment including sales tax, down payment, and trade-in value. See the total interest over your loan term.
In many states, a trade-in reduces the taxable amount of your purchase, lowering the sales tax you pay. This calculator applies tax after subtracting the trade-in.
A 72 or 84-month loan lowers the payment but sharply increases interest and the risk of owing more than the car is worth.
An auto loan finances a vehicle purchase with fixed monthly payments over a set term, using the car itself as collateral. Because the loan is secured by the vehicle, rates are often lower than unsecured personal loans — but the same amortization math applies, and the total cost depends heavily on the price, your down payment, the interest rate, and how long you stretch the term.
This calculator shows your monthly payment and the total interest you will pay, so you can compare financing offers and see how a bigger down payment or shorter term changes the real cost of the car.
Auto loans amortize using the standard formula:
M = P × [ r(1+r)n ] / [ (1+r)n − 1 ]
The financed amount P is the vehicle price plus taxes and fees, minus your down payment and any trade-in value. r is the monthly rate and n is the number of months.
Finance a $35,000 car with $5,000 down over 5 years at a 7% APR (financing $30,000):
| Figure | Value |
|---|---|
| Monthly payment | $594 |
| Total paid | $35,640 |
| Total interest | $5,640 |
Stretching the same loan to 7 years lowers the payment to about $453 but raises total interest to roughly $8,050 — and for much of that time you may owe more than the car is worth.
A larger down payment reduces the financed amount and the interest on it, and helps you stay above water as the car depreciates. Many advisors suggest at least 20% down on a new car.
Longer terms (72 or 84 months) lower the monthly payment but add substantial interest and increase the risk of negative equity. Shorter terms cost more monthly but far less overall.
Used cars usually carry higher interest rates than new ones, but they also depreciate more slowly since the steepest drop already happened. The lower purchase price often outweighs the higher rate.
Estimates are for educational purposes only and are not financial advice. Actual terms vary by lender, vehicle, and creditworthiness.