Auto Loan Calculator
Calculate your real car payment including sales tax, trade-in credit, title and registration fees — plus the total interest a longer loan term actually costs you.
Your combined state and local rate.
The payment the dealer quotes is not the payment you make
A dealer quotes a monthly figure. What lands on your loan is the price plus sales tax, plus title, registration and documentation fees — often several thousand dollars more than the sticker.
This calculator starts from the out-the-door number instead, because that is what you are actually financing.
Your trade-in is worth more than its value
Enter a trade-in and watch the sales tax line drop. In most states, tax is charged on the price after the trade-in is deducted.
So a $10,000 trade-in in a 7% state saves you $10,000 off the price and about $700 in tax. That is a real reason to trade in rather than sell privately — the tax saving can close much of the gap between the dealer’s offer and a private sale price. Worth doing the arithmetic both ways.
Long terms are how expensive cars get sold
Seven-year car loans are common now, and they exist to make an unaffordable payment look affordable.
Run the same car at 60 and 84 months and compare the total interest line, not the payment. The gap is usually thousands of dollars. Worse, cars depreciate far faster than an 84-month loan amortizes, so you spend most of the term owing more than the vehicle is worth — which becomes a genuine problem if you need to sell it, or if it is totaled.
A useful rule: if the payment only works at 72 months or longer, that is information about the car, not about the loan.
Before you sign
- Get pre-approved at a bank or credit union first. It costs nothing and gives the dealer something to beat.
- Negotiate the price, not the payment. A dealer can hit almost any monthly figure by stretching the term.
- Decline the add-ons. Extended warranties, paint protection and VIN etching are high-margin and rarely worth financing at your loan’s interest rate.
- Check the doc fee against your state’s cap, if it has one.
How this is calculated
Taxable amount = vehicle price − trade-in value Sales tax = taxable amount × your combined tax rate Amount financed = price − trade-in − down payment + sales tax + fees Monthly payment = loan × r ÷ (1 − (1 + r)^−n), r = APR ÷ 12 Total cost = all payments + down payment
Frequently asked questions
- Does my trade-in reduce the sales tax I pay?
- In most states, yes. Sales tax is charged on the price after the trade-in is deducted, so a $10,000 trade-in at a 7% rate saves about $700 in tax on top of the $10,000 credit. A handful of states tax the full price regardless, so confirm your state's treatment.
- Is a 72 or 84-month car loan a bad idea?
- It lowers the monthly payment and raises almost everything else. You pay substantially more total interest, and you stay underwater — owing more than the car is worth — for most of the term. If the only way the payment fits is a seven-year term, the honest conclusion is usually that the car is too expensive.
- What fees should I expect at the dealer?
- Title and registration are set by your state. Documentation fees are set by the dealer and vary from modest to several hundred dollars, capped in some states and not others. Dealer add-ons like paint protection and VIN etching are optional and usually poor value.
- Should I finance through the dealer or my bank?
- Get a pre-approval from a bank or credit union first, then let the dealer try to beat it. Dealer financing is sometimes genuinely cheaper thanks to manufacturer subsidies, but without a competing offer you have no way to tell.
- Does a bigger down payment help beyond the lower payment?
- Yes. It reduces total interest, shortens the time you spend owing more than the car is worth, and can qualify you for a better rate. It also protects you if the car is totaled early, when insurance pays market value rather than your loan balance.