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JustTools

Auto Loan Calculator

Work out your car payment the way the dealer will: price, rebate, trade-in and what you still owe on it, sales tax, fees and APR – then compare terms and decide between a low APR and cash back.

Runs in your browser Free · no sign-up

At a glance

  • Covers everything on the buyer’s order: vehicle price, cash rebate, down payment, trade-in value, what you still owe on the trade-in, sales tax and fees.
  • Example: a $35,000 car with an $8,000 trade-in ($3,000 owed), $3,000 down, 7% sales tax and $800 of fees at 6.5% APR for 60 months is $580.92 a month, with $5,165 of interest.
  • In most states the trade-in lowers the taxed price – $1,890 of tax instead of $2,450 in that example. California, Hawaii, Virginia and Washington DC tax the full price; Michigan limits the credit.
  • Negative equity – owing more on the trade-in than it is worth – is added to the new loan, and the calculator warns you when it is.
  • Shows the out-the-door price, the cash due at signing, the total of payments and the total cost with interest, and lets you pay tax and fees upfront or in the loan.
  • Low APR or cash back? On that example, 1.9% APR beats $2,500 cash back at 6.5% by $774. Compare any two offers.
  • Compares 36- to 84-month terms, estimates the price a monthly budget covers and builds the amortization schedule. Nothing you enter leaves your browser.

Step by step

How to calculate a car payment

  1. 1

    Enter the price and rebate

    Type the negotiated vehicle price, any cash rebate and your cash down payment.

  2. 2

    Add your trade-in

    Enter what the dealer gives for your current car and what you still owe on it.

  3. 3

    Set tax and fees

    Enter your sales tax rate, how your state treats trade-ins and rebates, and the title, registration and dealer fees.

  4. 4

    Choose the loan

    Enter the APR and pick a term from 36 to 84 months.

  5. 5

    Compare

    Read the payment and total cost, compare terms, and test a low-APR offer against cash back.

Features

Everything you need, nothing you don’t

Dealer math, made clear

Rebate, trade-in, payoff, tax and fees are applied in the right order, so the amount financed matches the buyer’s order.

Sales tax done properly

Choose whether your state credits the trade-in against tax and whether the rebate is taxed.

Negative equity flagged

See exactly how much of an old loan rolls into the new one, and what it does to the payment.

Low APR or cash back

Put a dealer’s special rate against a rebate with your own financing and see which costs less over the loan.

Term comparison

A table of 36- to 84-month payments and interest shows the real price of a lower payment.

Private

No sign-up and no dealer leads – the numbers stay on your device.

How the amount financed is worked out

Sales tax is charged on the price – less the trade-in in states that allow it, and usually before a manufacturer rebate. Whether fees such as the documentation fee are taxed varies by state; the calculator taxes the price only.

  • Price − rebate – what the car costs after incentives.
  • − trade-in equity – the trade-in value minus what you owe on it; if you owe more, the difference is added instead.
  • − down payment – cash you pay at signing.
  • + sales tax and fees – if you choose to finance them rather than pay them upfront.

Car payment by term

For $29,690 financed at 6.5% APR. Long terms lower the payment but more than double the interest, and leave you owing more than the car is worth for longer.

TermMonthly paymentTotal interest
36 months$909.97$3,069
48 months$704.10$4,107
60 months$580.92$5,165
72 months$499.09$6,244
84 months$440.88$7,344

FAQ

Frequently asked questions

How do I calculate my car payment?

Work out the amount financed – price, minus rebate, trade-in equity and down payment, plus any tax and fees you finance – then apply P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where r is the APR ÷ 12 and n the number of months. $29,690 at 6.5% for 60 months is $580.92.

Does a trade-in reduce sales tax?

In most states, yes: you pay sales tax only on the price minus the trade-in. California, Hawaii, Virginia and Washington DC tax the full price, and Michigan caps the credit. Check your state’s rules and set the switch to match.

What happens if I owe more than my trade-in is worth?

That negative equity is usually added to the new loan, so you pay interest on it and start the new loan upside down. Paying it off in cash, waiting until you have equity, or choosing a cheaper car avoids the trap.

Is 0% APR or cash back better?

It depends on the rebate, your own rate and the term. Enter both offers in Low APR or cash back? – the one with the lower total cost wins. Large rebates often beat a low rate on shorter loans; low rates win on longer ones.

What is the out-the-door price?

The full amount to buy the car: price minus rebates, plus sales tax and fees. Negotiating on the out-the-door price stops add-ons and fees from creeping in after you agree a price.

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