Auto Loan Payment Calculator
Estimate your monthly auto loan payment based on loan amount, annual interest rate, and repayment term. Useful when budgeting for a new or used car purchase before visiting a dealership.
About this calculator
Monthly auto loan payments are calculated using the standard amortization formula. If P is the principal (loan amount), r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the loan term in months, the monthly payment M is: M = P × r / (1 − (1 + r)^(−n)). This formula ensures that each payment covers both the interest accrued that month and a portion of the principal, so the loan is fully paid off by the final payment. Early in the loan, a larger share of each payment goes toward interest; as the balance decreases, more goes toward principal. Understanding this helps borrowers see why a longer term lowers monthly payments but increases total interest paid over the life of the loan.
How to use
Imagine you borrow $25,000 at a 6% annual interest rate for 60 months. First, find the monthly rate: r = 6 / 100 / 12 = 0.005. Then apply the formula: M = 25000 × 0.005 / (1 − (1 + 0.005)^(−60)). Calculate (1.005)^(−60) ≈ 0.7414, so the denominator = 1 − 0.7414 = 0.2586. M = 125 / 0.2586 ≈ $483.32 per month. Over 60 months you'll pay $28,999.20 total — meaning $3,999.20 in interest on top of the $25,000 principal.
Frequently asked questions
How does the loan term length affect my monthly auto loan payment?
A longer loan term spreads the principal over more payments, so each monthly payment is smaller. However, a longer term means interest accumulates over more months, significantly increasing the total amount paid. For example, a $20,000 loan at 5% costs about $377/month over 60 months ($2,645 total interest) but only $264/month over 84 months ($4,182 total interest). Choosing the shortest term you can comfortably afford minimizes the overall cost of the loan.
What interest rate should I expect on an auto loan?
Auto loan interest rates depend on your credit score, the lender, whether the car is new or used, and the current federal funds rate environment. As of recent years, borrowers with excellent credit (720+) may qualify for rates as low as 4–6% on new cars, while those with fair credit might see 10–15% or higher. Used car loans typically carry slightly higher rates than new car loans. Always get pre-approved by your bank or credit union before visiting a dealership to have a competitive benchmark rate in hand.
Why is my total repayment amount higher than the original loan amount?
The difference between your total repayment and the original loan amount is the interest — the cost of borrowing money over time. Each month, the lender charges interest on the remaining balance, and your payment covers that interest charge first before reducing the principal. Even a seemingly small interest rate compounds into a meaningful sum over a multi-year loan term. Making extra payments toward the principal whenever possible is one of the most effective ways to reduce the total interest you pay.