Auto Loan Calculator
See exactly what a car will cost you each month — before you visit the dealer. Enter the price, your down payment and trade-in, the APR and the loan term, and get your monthly payment, total interest and true total cost instantly.
Your car & loan
Tax note: when you add sales tax, it is calculated on price minus trade-in (as in most US states) and added to the amount financed, along with any fees.
Your result
How it works
First, the calculator works out how much you actually borrow. It takes the car price, adds any sales tax (on price minus trade-in, the way most states do it) and any fees you enter, then subtracts your down payment and trade-in value. That is your loan amount.
Then it uses the standard amortizing loan formula — the same one banks and credit unions use — with a monthly rate of APR ÷ 12:
Total amount paid is the exact monthly payment multiplied by the number of months, before the monthly figure is rounded to cents for display — which is why $534.63 × 60 can look a few cents different from the $32,077.94 total. Total interest is total paid minus the loan amount. Total cost of the car adds your down payment and trade-in back on top of all loan payments, so you see the full price of owning the car through the loan, not just the monthly number.
If the APR is 0%, the payment is simply the loan amount divided by the number of months, with no interest. Every payment splits into interest (on the remaining balance) and principal, so early payments are interest-heavy and later payments pay down the car faster.
Same $27,000 loan at 7% APR — what the term does
| Term | Monthly payment | Total interest | Total paid |
|---|
A shorter term costs more per month but far less overall. Going from 84 to 36 months on this loan saves $4,217.66 in interest ($7,230.20 − $3,012.54).
Before you sign: 4 things that change your payment
- Your credit score sets your APR. The same $27,000 loan costs thousands more at 12% than at 5%. Getting pre-approved by a bank or credit union before visiting the dealer gives you a rate to beat.
- Put more down if you can. Every $1,000 extra down on a 60-month, 7% loan saves about $19.80/month and about $188 in interest — and keeps you from owing more than the car is worth.
- Watch the term, not just the payment. Dealers can make almost any car “fit” a monthly budget by stretching the loan to 72 or 84 months. Compare total cost, not just the monthly figure.
- Budget beyond the loan. Insurance, fuel, maintenance, registration and repairs are not in this calculator. A common guide is the 20/4/10 rule: 20% down, a term of 4 years or less, and total car costs under 10% of gross monthly income.
Frequently asked questions
How is a monthly car payment calculated?
With the standard amortizing loan formula: your loan amount is multiplied by a factor based on the monthly interest rate (APR ÷ 12) and the number of payments. Each monthly payment covers that month's interest first, and the rest reduces your balance, so the interest share shrinks over time.
What is a good APR for a car loan in the USA?
It depends on your credit score, the term, and whether the car is new or used. Borrowers with excellent credit (roughly 780+) usually qualify for the lowest rates lenders advertise; fair or poor credit can mean double-digit APRs. There is no single “good” rate — compare at least two or three real offers, including a credit union, before accepting dealer financing.
Does a larger down payment lower my monthly payment?
Yes. Down payment and trade-in value come straight off the amount you borrow. On a 60-month loan at 7% APR, every extra $1,000 down lowers the payment by about $19.80 a month and saves about $188 in interest over the full term.
Is a 72- or 84-month car loan a good idea?
It lowers the monthly payment, but you pay much more interest and stay “upside down” (owing more than the car is worth) for longer, which is risky if the car is totaled or you need to sell. For most buyers, 36–60 months is the safer range; this calculator's comparison table shows the real cost of each term side by side.
What is included in the total cost of the car?
Here, total cost = down payment + trade-in value + every loan payment (principal + interest), plus any tax and fees you chose to finance. It does not include insurance, fuel, maintenance or repairs, so budget for those separately.
Can I use this calculator for a used car or a refinance?
Yes. The math is identical for new, used and refinanced auto loans — only the price, APR and term change. For a refinance, enter your current payoff balance as the “car price” with $0 down and $0 trade-in.
Is my data saved when I use this calculator?
No. Everything is calculated instantly in your browser. ToolNly does not save, send or share the numbers you enter, and there is no account or login.
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