Out-the-door price: how to calculate what a used car really costs
The out-the-door price adds tax, title, registration and dealer fees to the car's price. Here's what's in it, a line-by-line Houston dealer quote, and how to get a written quote.
By the LotGauge team
Out-the-door price is the number that matters
The out-the-door (OTD) price is the total you'll pay to drive the car away: the vehicle price plus sales tax, government title and registration fees, and any dealer fees, before your down payment or trade-in. Negotiating the OTD price instead of the sticker price stops surprise fees from appearing at the finance desk.
What goes into it
Vehicle price: the negotiated price of the car. Sales tax: set by your state and sometimes your locality; see how used-car sales tax works. Title and registration: government fees that vary by state and vehicle. Documentation ("doc") fee: the dealer's paperwork charge; some states cap it, others don't. Add-ons: items like paint protection, VIN etching, nitrogen tires or service contracts. These are optional and negotiable.
Worked example: a Houston dealer quote, line by line
Say a Houston dealer quotes a used car at $24,000, and you're trading in a paid-off car they value at $8,000. Here's how the out-the-door price builds up:
Vehicle price: $24,000. Doc fee: $225, the amount Texas regulators presume is reasonable on a financed sale. Sales tax: Texas charges 6.25% on the price minus your trade-in, so 6.25% of $16,000 = $1,000. Title and registration: $35.50, which is Harris County's $33 title fee plus $2.50 to transfer a current registration (more if the registration needs renewing). Out-the-door price: $25,260.50.
Subtract the $8,000 trade-in and $2,000 down, and you finance $15,260.50. At 8.81% APR over 60 months, that's $315.38 a month and $3,662 in interest, before insurance. Open this quote in the calculator.
Two things to notice. Without the trade-in credit, the tax would be $1,500, so the trade saves you $500 on top of its $8,000 value. And every $1,000 of add-ons on this loan adds about $21 a month and $1,240 in total payments, so cross off anything you didn't ask for. Buying from a private seller instead? See private seller vs. dealer.
Ask for an itemized OTD quote in writing
Before visiting, ask the dealer to email an itemized out-the-door quote for the specific VIN. Compare quotes on the OTD total, not the advertised price. Question any add-on you didn't ask for, and remember that a lower monthly payment achieved by stretching the loan term is not a lower price.
Run the numbers
The car payment calculator builds the out-the-door price for you from the vehicle price, tax, title fees and dealer fees, then shows the amount financed, monthly payment and total interest.
Sources
Texas Comptroller, Motor Vehicle Sales and Use Tax. Harris County Tax Office, Buying a Used Motor Vehicle. Texas Office of Consumer Credit Commissioner, documentary fee rule (2024). Experian, average used-car loan rates by credit score (Q2 2026). Checked October 2026. The quote is an example, and payments were calculated with LotGauge's calculator.