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Auto Loan Calculator — Your Real Monthly Car Payment

Estimate your real monthly car payment — including sales tax and your trade-in. Enter the vehicle price, down payment, trade-in value, sales tax rate, APR, and term to see the amount financed and the total interest you’ll pay.

Your numbers

$

The negotiated price before tax, down payment, or trade-in.

$

Cash paid up front. Lowers the amount financed.

$

Value of your trade-in. Also lowers the taxable amount in most states.

%

Your state/local sales tax rate, e.g. 7.25.

%

Your quoted annual rate, e.g. 6.5.

yr

Repayment period in years; 5 (60 mo) and 6 (72 mo) are common.

Results

Monthly payment$569.37
Amount financed$29,100.00
Sales tax$2,100.00
Total interest$5,062.49
Total of payments$34,162.49
Number of payments60

The sticker price is rarely what you actually finance. An auto loan rolls in sales tax, then subtracts your down payment and trade-in to arrive at the real amount financed — and that figure, not the price, drives your monthly payment. This calculator assembles all of those pieces so the number you see reflects what you’ll truly pay each month and over the life of the loan.

What goes into the amount financed

  • Vehicle price is the negotiated price of the car before anything else.
  • Sales tax is added on top. In most US states the tax is calculated on the price after your trade-in is subtracted — the trade-in tax credit — so a trade-in lowers both your loan and your tax bill. (A few states, such as California and Virginia, tax the full price; if you live in one, leave the trade-in field at zero.)
  • Down payment and trade-in value are then subtracted, because that money never gets financed. What’s left is the amount the lender actually loans you.

Once we have the amount financed, it’s amortized with the standard loan formula — the same EMI engine behind every loan tool on WorthAxis — to produce a fixed monthly payment.

A worked example

Take a $35,000 vehicle with $3,000 down, a $5,000 trade-in, 7% sales tax, financed at 6.5% APR over 5 years (60 months):

  • Taxable amount: $30,000 ($35,000 − $5,000 trade-in)
  • Sales tax: $2,100 (7% of $30,000)
  • Amount financed: $29,100 ($35,000 + $2,100 − $3,000 − $5,000)
  • Monthly payment: about $569.37
  • Total interest: about $5,062.49
  • Total of payments: about $34,162.49

Notice the trade-in pulls double duty: it cuts the taxable amount and the amount financed. Dropping the trade-in to zero would raise both your tax and your loan, lifting the monthly payment noticeably.

How to lower your car payment

  • Put more down. A larger down payment or trade-in shrinks the loan directly and keeps you in positive equity sooner — important because cars depreciate fast.
  • Shop the APR. Rates vary widely by credit score and by new vs. used. Get pre-approved through a bank or credit union before you visit the dealer so you have a benchmark to beat.
  • Keep the term short. A 72- or 84-month loan lowers the payment but stacks up interest and raises the risk of being “underwater.” A 48- or 60-month term costs less overall.
  • Mind the tax. Sales tax rates differ by state and locality; using your real rate keeps the estimate honest, since on a $35,000 car a couple of percentage points is real money.

Reading your results

Use the monthly payment to check the car fits your budget, and the total interest to compare financing offers. If two loans show the same payment, the one with the shorter term almost always costs less. Adjust the inputs above to test scenarios — a bigger down payment or a shorter term changes the picture quickly.

Estimates are for planning only and exclude dealer fees, registration, and extended warranties, and assume tax is financed with the loan. Your lender’s quote is the authoritative figure — see our disclaimer.

Frequently asked questions

How is a monthly car payment calculated?
First we work out the amount financed: the vehicle price plus sales tax, minus your down payment and trade-in value. That amount is then amortized with the standard loan formula — payment = P · r / (1 − (1 + r)^−n), where P is the amount financed, r is the monthly rate (APR ÷ 12), and n is the number of months. The result is your fixed monthly payment.
Does a trade-in reduce the sales tax on a car?
In most US states, yes. Your trade-in value is subtracted from the vehicle price before sales tax is applied — the "trade-in tax credit" — so a $5,000 trade-in on a $35,000 car means you’re taxed on $30,000. A few states (such as California and Virginia) tax the full price; if you’re in one of those, leave the trade-in field at zero and lower the price instead.
Is sales tax included in my car loan?
It can be. Most buyers roll sales tax into the loan rather than paying it in cash, so this calculator adds the tax to the amount financed by default. Your down payment and trade-in are then subtracted from that total. If you plan to pay the tax up front, add it to your down payment.
What APR and term are typical for an auto loan?
US auto loan APRs commonly range from about 5% for new cars with strong credit to well over 15% for used cars or weaker credit. Terms run from 36 to 84 months; 60 (5 years) and 72 (6 years) are the most common. Longer terms lower the payment but add interest and raise the risk of owing more than the car is worth.
Should I choose a longer loan term to lower my payment?
A longer term shrinks the monthly payment but increases the total interest, and because cars depreciate quickly you can spend years "underwater" — owing more than the vehicle’s value. A larger down payment or a shorter term keeps you in positive equity sooner and costs less overall.

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