How the Auto Loan Calculator works
Your car loan is based on the amount financed, not the sticker price. We first subtract your down payment and any trade-in value from the vehicle price, then calculate a standard fixed monthly payment on the remaining balance.
A bigger down payment or trade-in reduces the amount financed, which lowers both your monthly payment and the total interest you'll pay over the loan.
Remember that this calculator only covers the financed amount — sales tax, title, registration, and dealer fees are not included and will change your actual out-the-door numbers.
A worked example
A $32,000 car with $3,000 down and no trade-in means a $29,000 loan. At 6.9% over 5 years the payment is $572.87, and you pay $5,372.05 in interest — total cost $34,372.05 for the financed portion.
| Term | Monthly payment | Total interest |
|---|---|---|
| 3 years | $893.94 | $3,182 |
| 5 years | $572.87 | $5,372 |
| 7 years | $436.31 | $7,650 |
A 7-year loan is roughly $136 a month cheaper than a 5-year, but costs about $2,280 more in interest — and you may owe more than the car is worth for much of the term.
How to read your results
The loan amount is price − down payment − trade-in equity (plus tax and fees if your state finances them). The payment shown is principal and interest only; registration, and especially insurance, are on top.
When to use this calculator
Use it before you set foot on a lot, so you negotiate on the total price, not the monthly payment — the figure dealers are trained to steer you toward. Bring a pre-approval from your bank or credit union as a benchmark.
Common mistakes to avoid
- Negotiating by monthly payment. It hides a longer term, a higher price, or costly add-ons.
- Rolling negative equity into the new loan. You start the next car already underwater.
- Stretching to 72 or 84 months. Lower payment, far more interest, and years of being upside-down.
- Forgetting gap insurance on a long, low-down-payment loan. If the car is totaled, you could owe more than it pays out.