How to use
- Enter the vehicle price, your down payment, the interest rate and the term in months.
- Trading in a car? Add its trade-in value and what you still owe on it.
- Enter your sales tax rate, choose how your state taxes trade-ins, and add fees such as title and registration.
- Choose whether tax and fees go into the loan or are paid upfront.
- Compare terms, then open the schedule to see every payment.
How the car payment is calculated (formula)
Amount financed = price + tax + fees − down payment − (trade-in value − amount owed)
Monthly payment = A × r × (1 + r)^n ÷ ((1 + r)^n − 1)
- A is the amount financed. Leave out tax and fees if you pay them upfront.
- r is the monthly rate: yearly rate ÷ 12 ÷ 100.
- n is the number of monthly payments.
These are the cost lines on the CFPB’s auto loan shopping sheet: price, add-ons, taxes, fees, then minus the down payment and trade-in.
Example
CFPB’s worked example: a $20,000 car with $300 of add-ons, $1,400 of taxes and title, and $100 of fees costs $21,800. After $3,000 down and a $3,000 trade-in, $15,800 is financed.
- At 3.5% for 48 months, the payment is $353.22 a month.
- Total interest is about $1,155.
This calculator’s default: $35,000 with 6% tax, $600 of fees and $3,500 down means $34,200 financed. At 7% for 60 months, you pay $677.20 a month and $6,432.07 in interest.
Payment by loan term
For $34,200 at 7%:
| Term | Monthly payment | Total interest |
|---|---|---|
| 36 months | $1,056.00 | $3,815.89 |
| 48 months | $818.96 | $5,110.16 |
| 60 months | $677.20 | $6,432.07 |
| 72 months | $583.08 | $7,781.42 |
| 84 months | $516.17 | $9,158.29 |
A longer term cuts the payment but more than doubles the interest here.
Sales tax on a trade-in
States differ, so pick the option that matches yours:
- Price minus trade-in: Texas taxes only the difference. A $25,000 car with a $10,000 trade-in is taxed on $15,000.
- Full price: California taxes the whole price, with no credit for the trade-in.
In the default example, a $10,000 trade-in cuts the tax from $2,100 to $1,500 where the credit applies.
Owing more than your trade-in is worth
This is negative equity. The dealer usually adds the gap to your new loan, and you pay interest on it.
With an $8,000 trade-in and $10,000 still owed, the default loan grows to $35,720 and the payment to $707.30 a month.
How rounding works
Sales tax is rounded to the cent. Each payment and each month’s interest is rounded to the cent too, and the last payment is adjusted so the balance ends at exactly zero.
That is why the total can differ by a few cents from the payment × the number of months.
For a loan without a car purchase, try the general loan calculator.