Auto Loan Calculator
Auto Loan Calculator: Enter the vehicle price, down payment, trade-in value, APR and loan term to estimate your monthly car payment and the total interest you'll pay over the life of the loan.
Data as of 2026-06-14.
Estimates only — for general education, not financial advice. See our disclaimer.
The formula
M = L · r / (1 − (1 + r)⁻ⁿ)
where L is the amount financed (vehicle price − down payment − trade-in), r is the monthly rate (APR ÷ 12) and n is the term in months. Total interest is the sum of payments minus the amount financed.
How it works
- The amount you finance is the price minus your down payment and trade-in value.
- A longer term lowers the monthly payment but increases total interest — and raises the risk of being underwater.
- APR already bundles most loan fees, so it's the rate to compare across lenders.
- Sales tax, title and dealer fees are not included here and vary by state.
Frequently asked questions
How is a car loan payment calculated?
The amount financed (price minus down payment and trade-in) is amortized over the term at the loan's monthly rate using M = L·r/(1−(1+r)⁻ⁿ). Longer terms mean smaller payments but more total interest.
Is a longer auto loan term cheaper?
Only month to month. A 72- or 84-month loan has a lower payment than a 60-month loan but you pay more interest overall and risk owing more than the car is worth.
Should I put more money down on a car?
A bigger down payment lowers the amount financed, your monthly payment and total interest, and reduces the chance of negative equity if the car depreciates faster than you pay it off.
What APR should I expect on a car loan?
Rates depend heavily on your credit score, the lender and whether the car is new or used. Always compare the APR (not just the monthly payment) across at least two or three lenders. This tool is an estimate, not financial advice.
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Last updated: 2026-06-14