Auto Loan Calculator

How our auto loan calculator works

Buying a car means signing up for a monthly payment, but that single number hides a lot of math. The payment depends on the amount you finance, the annual interest rate, and how many months you stretch it over. Change any one of those and the others ripple. Our calculator runs the same standard amortization formula that banks and credit unions use, so the numbers you see here match the numbers you'll see on a real loan disclosure.

Plug in your vehicle price, down payment, trade-in value, interest rate, and loan term. The calculator instantly shows your monthly payment, total interest paid over the life of the loan, and the full cost. Toggle on extra monthly payments to see exactly how much interest you'd save and how many months you'd shave off the loan.

The amortization formula, explained

The math behind any fixed-rate auto loan is one equation:

M = P × r × (1 + r)ⁿ / ((1 + r)ⁿ − 1)

• M = monthly payment
• P = principal (vehicle price minus down payment minus trade-in)
• r = monthly interest rate (annual APR divided by 12, expressed as a decimal)
• n = number of monthly payments (years × 12)

Every month, your payment is split into two parts: interest on the remaining balance and principal that chips away at what you owe. Early in the loan, most of your payment goes to interest. As the balance falls, more of each payment goes to principal. That curve is your amortization schedule.

A worked example

Say you're financing a $30,000 vehicle, putting $5,000 down, with no trade-in, at 6.5% APR over 60 months.

• Principal (P) = $30,000 − $5,000 = $25,000
• Monthly rate (r) = 0.065 / 12 = 0.00541667
• Number of payments (n) = 60
• Monthly payment (M) ≈ $489.05
• Total paid over 60 months = $29,343
• Total interest = $4,343

Now add a $50/month extra payment. The loan pays off about 7 months early, and total interest drops to roughly $3,650 — a savings of around $700. That's the power of attacking principal directly.

What changes your monthly payment

Interest rate

The single biggest lever. A 2-point swing in APR — say 6% to 8% on a $25,000, 60-month loan — adds roughly $25 per month and over $1,400 in total interest. Your credit score, the loan term, whether the vehicle is new or used, and current market conditions all influence the rate you're offered.

Loan term

Longer terms lower the monthly payment but compound interest over more months. 84-month auto loans have become common but rarely make sense: by the time the loan is paid off, the vehicle is often near the end of its useful life, and you've paid thousands more in interest than a 60-month version of the same loan.

Down payment and trade-in

Both reduce the principal you finance dollar-for-dollar. A bigger down payment also helps you avoid being upside-down — owing more than the car is worth — which is especially important on new vehicles that lose roughly 20% of their value in the first year.

Extra monthly payments

Because auto loans use simple interest (the rare exception aside), every extra dollar you put toward principal reduces the interest charged on every future month. Even small extras add up — try the "Extra Monthly Payment" field in the calculator above to see your exact savings.

Typical auto loan rates in 2026

Rates vary by credit tier, loan term, new vs. used, and lender type. The ranges below reflect typical offers seen across major banks and credit unions in 2026 — your offer will depend on your specific credit profile.

• Excellent credit (780+): roughly 5.0% – 6.5% APR on new, slightly higher on used
• Good credit (700–779): roughly 6.5% – 8.5%
• Fair credit (620–699): roughly 9% – 13%
• Subprime (below 620): often 15%+, with some lenders much higher

Credit unions almost always quote lower rates than dealer F&I or large banks — they're worth a 15-minute pre-approval call before you shop.

Glossary

• APR (Annual Percentage Rate): the all-in yearly cost of borrowing, including fees. Use this to compare offers.
• Principal: the amount you're actually borrowing.
• Amortization: the process of paying down a loan with regular payments split between principal and interest.
• Negative equity: owing more on the loan than the vehicle is currently worth.
• GAP insurance: coverage that pays the difference between what you owe and the vehicle's actual cash value if it's totaled.
• LTV (Loan-to-Value): the loan amount divided by the vehicle's value. Lenders use this to price risk.

Want to learn more? Read our guide on how much car you can afford on a $60k salary or check out auto loan interest rates by credit score.