About the Auto Loan Calculator

Buying a car is one of the largest purchases most people make, and understanding your monthly car payment before visiting the dealership puts you in a stronger negotiating position. This auto loan calculator factors in your vehicle price, down payment, and trade-in value to give you an accurate estimate of what you will pay each month. It uses the standard amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal (price minus down payment and trade-in), r is the monthly interest rate, and n is the total number of monthly payments.

The difference between a 3-year and a 6-year auto loan can be dramatic. A shorter term means higher monthly payments but significantly less total interest paid. For example, financing $30,000 at 6.5% for 3 years costs about $3,090 in interest, while the same loan over 6 years costs about $6,360 — more than double. Understanding these trade-offs helps you choose a term that fits both your monthly budget and your long-term financial goals.

This calculator also accounts for down payments and trade-in values, which reduce the amount you need to finance. A larger down payment lowers your monthly payment and total interest cost. Financial experts typically recommend putting at least 20% down on a new car and 10% on a used car to avoid being "upside down" on your loan — owing more than the car is worth.