How Auto Loan Payments Are Calculated

Auto loan payments use the same amortization formula as mortgages. The loan amount equals the vehicle price minus your down payment and trade-in value.

Loan Amount = Vehicle Price - Down Payment - Trade-In Monthly Payment = Loan × [r(1+r)^n] / [(1+r)^n - 1] r = Annual Rate / 12, n = Loan Term in months

Frequently Asked Questions

As of 2025-2026, good rates for new cars range from 4-6% for excellent credit (750+), 6-9% for good credit (670-749), and 9-14% for fair credit (580-669). Used car rates are typically 1-2% higher.
Shorter terms (36-48 months) have higher monthly payments but lower total interest. A 60-month loan on $30,000 at 6% costs $2,400 more in interest than a 36-month loan. Avoid 72-84 month loans if possible — you'll likely owe more than the car is worth.
A trade-in reduces the amount you need to finance. If you're buying a $35,000 car with a $10,000 trade-in and $5,000 down, you only finance $20,000. This lowers your monthly payment and total interest.
This calculator shows the loan payment only. Sales tax (varies by state, typically 4-10%), registration fees, and dealer fees will add to your total cost. Add these to the vehicle price for a more complete estimate.

Financing Tip

Get pre-approved by your bank or credit union before visiting the dealer. This gives you leverage to negotiate and a baseline rate to compare against dealer financing.