Automotive & Finance

Auto Loan Calculator

Calculate your true out-the-door monthly car payment including trade-in tax savings, sales tax, and dealership fees.

Out-The-Door Price
Trade-in Tax Savings
Dealership Fees
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Auto Finance Tool

Advanced Car Payment Estimator

Calculate the true cost of financing a vehicle.

Updated for 2026⚡ Instant Results

Vehicle Details

Out-the-Door Price

Taxes & Dealership Fees

In most states, trading in a car reduces your taxable amount. Your trade-in is saving you $350 in sales tax!

Estimated Monthly Payment

$599

Financed Amount: $29,900

Principal (Car Value)
$29,900
Total Interest
$6,048
Taxes & Fees
$2,900

Out-the-Door Price

$32,900

Car + Tax + Fees - Trade

Total Interest Paid

$6,048

Over 60 months

All calculations run locally in your browser • No data stored • For estimation purposes only

Car Buying Rules of Thumb

20%

Ideal Down Payment

Prevents being underwater

60 Mo

Max Loan Term

Avoid 72+ month loans

10%

Transportation Rule

Max % of income for car+ins

Pre-Approval

Dealer Leverage

Bring your own bank rate

Never Negotiate the Monthly Payment

Trade-Ins · Taxes · Out-The-Door Prices

The biggest mistake you can make at a dealership is answering the question: "What monthly payment are you looking for?" Dealerships use the "Four Square" method to manipulate loan terms, interest rates, and trade-in values to hit your monthly payment, usually resulting in you paying thousands more for the car.

Always Negotiate the "Out-The-Door" Price

You should only negotiate one number: the Out-The-Door (OTD) price. This is the final amount required to buy the car, including the negotiated car price, your trade-in, state sales tax, title fees, and the dealership's doc fee.

  • Get Pre-Approved: Bring an interest rate from your local bank or credit union before walking into the dealership.
  • Separate the Trade: Negotiate the price of the new car first, then discuss your trade-in.

The Hidden Trade-In Tax Advantage

In over 40 US states, trading in your vehicle at the dealership provides a massive tax break. You only pay sales tax on the difference between the new car price and your trade-in. For example, trading in a $10,000 car with a 7% state tax rate saves you $700 in pure cash. Our calculator automatically factors this in!

The Trap of 72 and 84-Month Loans

To keep monthly payments low on increasingly expensive cars, dealerships now push 72 and 84-month (7-year) loans. This is extremely dangerous. Cars depreciate quickly. If you take out a 7-year loan with a small down payment, you will likely be "upside down" (owing more than the car is worth) by year two. If the car is totaled or you want to sell it, you will have to write a massive check to the bank just to get rid of it.

Aim to follow the 20/4/10 Rule: Put 20% down, finance for no longer than 4 years (48 months), and keep total car expenses (payment + insurance) under 10% of your gross income.

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FAQ

Auto Financing Questions

Does a trade-in reduce my sales tax?
In most US states, yes! If you buy a $30,000 car and trade in a $10,000 car, you only pay sales tax on the $20,000 difference. This is a massive hidden benefit of trading in your car at the dealership rather than selling it privately.
What is an 'Out-The-Door' price?
The Out-The-Door (OTD) price is the absolute final total you will pay to drive the car off the lot. It includes the negotiated price of the car, plus state sales tax, title/registration fees, and dealership documentation fees, minus your trade-in value.
Should I take a 72 or 84 month loan?
Financial experts strongly recommend against loans longer than 60 months. While a 72 or 84-month loan lowers your monthly payment, the interest rate is usually much higher. More importantly, cars depreciate quickly, meaning you risk being 'upside down' (owing more than the car is worth) for years.
What are dealership 'Doc Fees'?
Documentation fees (Doc Fees) are what the dealership charges to process the paperwork for your sale. Some states legally cap this fee (e.g., California caps it at $85), while in other states (like Florida), dealerships routinely charge $800 to $1,200.