CalcDime

Auto Loan Calculator

Your monthly car payment after the down payment, trade-in and sales tax, and what the car really costs once interest is included.

Reviewed November 2026How we calculate

Trade-in & fees

Monthly payment$0
Amount financed$0
Total interest$0
Sales tax$0
Due at signing$0
Total cost of the car$0

Same car, different terms

Same rate for every term; lenders often charge more for longer loans.

TermMonthly paymentTotal interestTotal of payments
Month-by-month payoff schedule
PaymentPrincipalInterestBalance

How the payment is calculated

The amount financed starts with the vehicle price, subtracts your down payment and trade-in value, and adds anything still owed on the trade-in. If you finance tax and fees, those are added too. The monthly payment then follows the standard installment-loan formula.

M = P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)

P is the amount financed, r is the APR divided by 12, and n is the number of months. Sales tax is charged on the price minus the trade-in.

Getting a better deal on the loan

  • Arrive with a pre-approval. A rate from your bank or credit union gives you a number the dealer has to beat.
  • Negotiate price and financing separately. A low monthly payment can hide a longer term or a higher price.
  • Watch the term. The table above shows how much more interest a 72- or 84-month loan costs for the same car.
  • Question add-ons. Extended warranties and GAP coverage are optional and can often be bought cheaper elsewhere.

What the total cost means

Total cost adds what you pay at signing, every monthly payment and the equity you hand over with your trade-in. It is the full price of owning the car through payoff, before insurance, fuel and maintenance. If the payment strains your budget, the paycheck calculator shows your monthly take-home, and the personal loan calculator handles private-party purchases.

Common questions

Does a trade-in reduce sales tax?

In most states, yes — sales tax is charged on the price minus the trade-in value. A few states, including California, tax the full price. This calculator applies the trade-in credit; if your state does not allow it, set the trade-in to $0 and add its value to the down payment.

What happens if I still owe money on my trade-in?

If you owe more than the car is worth (negative equity), the dealer usually adds the difference to the new loan. You then pay interest on debt from a car you no longer own. Enter the payoff amount above to see the effect.

Is a 72- or 84-month loan a bad idea?

Longer terms lower the payment but add interest, and they usually come with a higher rate. Because cars lose value quickly, a long loan also keeps you owing more than the car is worth for longer, which hurts if it is totaled or you want to sell.

What is not included?

Extended warranties, GAP insurance, service contracts and auto insurance premiums. If the dealer adds products to the loan, include them in the fees field.

Sources

Results are estimates for educational use and are not financial, tax or legal advice. Confirm figures with your lender, plan administrator or a tax professional before you act. Spotted an error? Tell us.