Vehicle
Trade-In Value Impact
See your equity, the sales tax a trade-in saves, what rolled-over negative equity really costs, and whether selling it yourself comes out ahead.
Your current vehicle
The new vehicle
Trade in vs. sell it yourself
| Trade in | Sell yourself | |
|---|---|---|
| Price you get | $15,000 | $17,500 |
| Sales tax on new | $1,365 | $2,340 |
| Amount financed | $40,365 | $38,840 |
| Payment | $688 | $662 |
Selling yourself means listing it, meeting buyers, and handling the payoff and title. The dollar gap is what that work is worth.
What this means
You owe $18,000 on a vehicle the dealer values at $15,000, so $3,000 of old debt rides along on the new loan. Over 72 months it costs about $683 in interest on top of itself, $3,683 in all, and the new vehicle starts out underwater too. Paying that gap in cash, or driving the current one a little longer, breaks the cycle.
Selling it yourself for $17,500 comes out about $1,872 ahead over the life of the loan, even after giving up the $975 tax break. Worth it if you have the time to sell.
Negotiate the trade-in and the new price as two separate deals. A generous trade-in offer can hide a higher price on the new vehicle.
These are estimates to help you think, not personalized legal, tax, or investment advice, and not a promise of any result.
This calculator shows what trading in your current vehicle does to the deal on the next one. Enter the dealer's offer and what you still owe, and it works out your equity, the sales tax the trade-in saves, the new amount financed, and the payment with and without the trade. If you owe more than the offer, it shows the extra interest you'd pay on that rolled-over debt.
Why it matters: a trade-in feels like free money off the new vehicle, but it can just as easily add debt to it. When you owe more than it's worth, the gap gets added to the new loan and charged interest for years. Add a price you could get selling it yourself and the calculator also shows whether the convenience of trading in is worth what it costs.
How to use it
Get the real payoff amount
Call your lender or check the app for the payoff amount, not the statement balance. It includes interest up to the payoff date.
Check how your state taxes trade-ins
Most states charge sales tax only on the new price minus the trade-in. A few charge it on the full price. Pick the one that matches your state.
Add a private-sale price, if you'd consider it
A realistic number from a used-car pricing site or local listings for the same model, year and miles. Leave it at $0 to skip that comparison.
Behind the numbers
Equity, positive and negative
Equity is the trade-in offer minus what you still owe. Positive equity works like a down payment. Negative equity (being underwater) means you owe more than the offer, and the difference has to be paid somehow, usually by adding it to the new loan.
The trade-in tax break
In states that tax only the difference, trading in means you don't pay sales tax on the trade-in amount. At a 6.5% rate, a $15,000 trade-in saves $975. Selling privately gives up that break, so a private sale has to beat the offer by more than the tax saved to come out ahead.
Rolling negative equity
The old debt rides along on the new loan and is charged interest for the full new term. It also means the new vehicle starts out underwater, which makes the next trade-in harder. It's how people end up carrying two or three vehicles' worth of debt on one loan.
The math behind it
Equity is the offer minus the payoff. Sales tax with a trade is the tax rate times the new price minus the offer (or the full price, in states without the break). The new amount financed is the price plus that tax, minus equity, which adds the debt when equity is negative. The extra interest on negative equity is the interest that amount alone would earn over the new loan's term. For a private sale, the tax is on the full price and what you get after paying off the old loan comes off the new one.
Worked example
A $15,000 offer on a vehicle with $18,000 still owed is $3,000 of negative equity. On a $36,000 vehicle with 6.5% sales tax charged on the difference, the trade saves $975 in tax, and the new loan is $40,365. At 7% for 72 months the payment is $688 a month, about $35 more than buying without the trade. The $3,000 of old debt costs about $683 in interest on top of itself. Selling it yourself for $17,500 instead comes out about $1,872 ahead over the life of the loan.
The private-sale break-even
Add the tax the trade-in saves to the dealer's offer. A private sale has to beat that number to come out ahead. With a $15,000 offer and $975 of tax saved, anything over $15,975 favors selling it yourself, before you count your time.
Common questions
What if I owe more than my car is worth?
You have negative equity. You can pay the difference in cash, keep driving the vehicle until the loan catches up with its value, or roll it into the new loan. Rolling it in is the easiest and the most expensive, and the calculator shows how much it costs.
Is it better to trade in or sell privately?
Selling privately usually gets a higher price, but in most states you give up the sales tax break, and you do the work of listing, meeting buyers and handling the title. The calculator puts a dollar figure on the difference so you can decide if it's worth your time.
Should I tell the dealer about a trade-in up front?
Many people negotiate the new price first and bring up the trade-in after, so a generous trade-in offer can't hide a higher price on the new vehicle. Either way, get a trade-in offer from more than one place so you know what yours is worth.
Go deeper
The calculator gives you a number. The Consumer Decisions & Big Purchases Brick teaches you what to do with it, in plain English. And if you’re not sure where to start, the free BrickScore Assessment checks your whole foundation in about 5 minutes.
first the number, then the move