Auto Loan Interest Calculator: See What Your Car Loan Really Costs
An auto loan interest calculator shows how much interest you'll pay over the full term of a car loan. Enter your loan amount, APR, and term in the calculator above to see your monthly payment and lifetime interest in seconds.
For example, a $30,000 loan with a 7.5% APR and a 60-month term costs $6,068 in total interest, bringing the total of all payments to $36,068.
How it's calculated
The calculator multiplies your loan balance by your APR each month, then splits every payment into interest and principal. Early on, more of each payment goes to interest, and less to paying down the loan. With a $30,000 loan at 7.5% APR, the very first payment of $601.14 includes $187.50 in interest and $413.64 in principal. The term you pick changes the math more than most buyers expect. That same $30,000 loan at 7.5% costs $6,068 in interest over 60 months, but $7,347 over 72 months. The 72-month loan lowers your payment to $518.70, yet it costs $1,278 more in interest. A lower monthly payment can hide a higher total cost.
A worked example
Say you buy a $35,000 vehicle and put $5,000 down. You finance $30,000 at 7.5% APR over 60 months.
The calculator shows a monthly payment of $601.14. Your first payment splits into $187.50 of interest and $413.64 of principal.
Over the full 60 months, you pay $6,068 in interest, for a total of $36,068. Stretch that same loan to 72 months and the payment drops to $518.70, but total interest climbs to $7,347.
The longer term costs you $1,278 more.
Common mistakes to avoid
- Shopping only by monthly payment. A smaller payment often means a longer term and more total interest, as the 60-vs-72-month gap of $1,278 shows.
- Confusing interest rate with APR. The CFPB notes APR includes the interest rate plus lender fees, so always compare APR to APR.
- Ignoring how the down payment shrinks interest. A larger down payment lowers the financed amount, so you pay interest on a smaller balance.
- Assuming the dealer's first quote is your best rate. The CFPB suggests getting preapproved and comparing offers from several lenders.
- Stretching the term just to afford a pricier car, which can leave you owing more than the vehicle is worth.
Frequently asked questions
What does an auto loan interest calculator tell me?
An auto loan interest calculator tells you the total interest you will pay over the life of your loan. It also shows your monthly payment and how each payment splits between interest and principal. For a $30,000 loan at 7.5% APR over 60 months, total interest is $6,068.
How does the loan term change my total interest?
A longer term lowers your monthly payment but raises your total interest. A $30,000 loan at 7.5% costs $6,068 in interest over 60 months, but $7,347 over 72 months. That longer term saves about $82 per month yet costs $1,278 more overall. Our guide to how long a car loan should be works through the full 36- to 84-month comparison.
What is the difference between APR and interest rate?
The interest rate is the cost of borrowing the principal. APR is the interest rate plus lender fees, such as origination charges, per the CFPB. APR is always equal to or higher than the interest rate, so compare APR to APR when shopping.
What is the average auto loan rate in 2026?
Rates change often, but Experian's mid-2025 data showed about 6.8% APR for new cars and 11.5% for used cars. Your own rate depends mostly on your credit score. Use the calculator above with a quote that fits your credit.
How can I pay less interest on my car loan?
Put more money down, choose the shortest term you can afford, and shop multiple lenders for a lower APR. You can also pay the loan off faster. Try our extra payment calculator or early payoff calculator to see the savings.
What APR should I expect based on my credit score, including with bad credit?
Your credit score moves your APR more than anything else in the loan, including the term or which lender you use. Experian's Q1 2026 data on used-car loans shows average APRs of 6.30% for super-prime borrowers (781+), 8.77% for prime (661-780), 14.03% for near-prime (601-660), and 19.42% or higher for subprime borrowers below 600. A subprime buyer financing the same $20,000 car as a super-prime buyer pays thousands more in total interest for the identical vehicle. Enter your own quoted APR into the calculator above to see exactly what your credit tier costs over the full loan.
Does this calculator include sales tax, fees, or trade-in value?
Enter your vehicle price net of any trade-in credit, since sales tax and fees vary too much by state and dealer to build into a single number. To see the true amount you're financing, add your state's sales tax to the price and subtract your trade-in's value before entering it as the vehicle price, then enter your actual cash down payment separately.
Sources
We prioritize primary sources for rules, formulas, rates, limits, and definitions. See our calculator methodology and editorial policy.