Should you trade in or sell privately? Count the tax credit, then decide
| Buyer | Typical Offer (% of private-party) | What You Give Up for the Convenience |
|---|---|---|
| Private sale (baseline) | 100% | Your time: ads, showings, paperwork, liability |
| Online instant buyer (Carvana, CarMax, Vroom-style) | 85–90% | Fastest and safest, widest discount |
| Franchise dealer trade-in | 88–92% | One-transaction convenience, tax credit applies |
| Independent used-car lot | 90–95% | Better price, rougher cars, still same tax credit |
The discount is the buyer's reconditioning and resale margin, so it widens on older, higher-mileage, or rough cars and narrows on clean late-model vehicles that can go straight to the front lot.
| Treatment | States / Territories | Effect on the Math |
|---|---|---|
| No credit (tax on full price) | California, Hawaii, Kentucky, Michigan, Virginia, Washington DC | Trading in saves $0 on tax; the higher private-sale price wins almost every time |
| No general sales tax | Alaska, Delaware, Montana, New Hampshire, Oregon | Tax is a non-issue; compare raw offer vs private net |
| Credit allowed (tax on difference) | The other ~40 states | Tax savings = trade-in value × your rate; can flip the verdict |
A few states and localities cap the deductible allowance on high-value trades, and older articles wrongly list Texas or Maryland as no-credit states; both allow the deduction now. Rules change, so confirm with your state revenue agency or DMV before you sign. This tool is an estimator, not tax or legal advice.
Everyone quotes two gross numbers: what the dealer will pay and what the car is "worth" privately. Neither is what you keep. This calculator runs the only comparison that matters, net proceeds on both paths, including the sales-tax angle most sellers forget.
Private net = private-party value − selling costs (detailing, small repairs, listing fees). Tax credit = trade-in offer × sales-tax rate in states that tax only the difference. Trade-in effective net = dealer offer + tax credit. Breakeven offer = private net ÷ (1 + tax rate) — the point where the two paths pay the same, expressed as a percentage of private-party value.
Look up your private-party value first (any pricing guide's private-party figure, not trade-in). Enter the best dealer or instant offer you've collected. Detailing and small repairs are the usual private-sale costs; skip them if you'd sell as-is. The replacement-car price and tax rate drive the credit, so fill those in only if you're buying another car.
Your car's private-party value is $20,000 and an online buyer offered $17,400 (87%). You're buying a $35,000 replacement in a 7% credit state.
Private path: $20,000 minus $450 in detailing, repairs, and listing costs = $19,550 net. Trade path: tax drops from $2,450 (7% of $35,000) to $1,232 (7% of the $17,600 difference), saving $1,218. So the trade's effective net is $17,400 + $1,218 = $18,618. Private wins by $932.
Now push the offer to 92% ($18,400). Effective net becomes $18,400 + $1,288 = $19,688, and the trade wins by $138. The breakeven sits at $18,271 — 91.4% of private value. And in a no-credit state like California, the 87% offer loses by the full $2,150, which is why the same offer can be a good deal in one state and a poor one in the next.
Selling privately usually nets more because dealer offers run about 85-92% of private-party value. But in the 40+ states that give a trade-in sales-tax credit, trading in lowers the tax on your replacement car, which closes part or all of the gap. On a $20,000 private value with a 7% tax rate, an 87% instant offer loses by about $932 after counting the $1,218 tax savings, while a 92% offer wins by $138.
Expect roughly 85-92% of private-party value from online instant buyers and franchise dealers. Independent used-car lots, which recondition less and sell cheaper inventory, often pay 90-95%. The gap is the dealer's reconditioning, flooring, and resale margin, so it is widest on rough or older cars.
California, Hawaii, Kentucky, Michigan, Virginia, and Washington DC tax the full purchase price of the new car with no trade-in deduction, so trading in saves you nothing on tax there. Alaska, Delaware, Montana, New Hampshire, and Oregon have no general sales tax at all. Old articles listing Texas or Maryland here are out of date; both now allow the deduction. Confirm with your state revenue agency before you sign.
In credit states you pay sales tax only on the difference between the new car's price and your trade-in allowance. Buy a $35,000 car with a $17,400 trade-in at 7% and you pay tax on $17,600 ($1,232) instead of on $35,000 ($2,450), saving $1,218. That saving is real money, so the fair comparison is dealer offer plus tax saved against private-sale proceeds minus selling costs.
Typically $300-$700: $100-$250 for detailing, $100-$400 for small repairs that make the car photograph well, $15-$75 for listing fees, and your state's title-transfer and smog or safety paperwork. Add the risk of lowballers, no-shows, and paperwork liability that a dealer takes off your hands. Price your time honestly: at 4-6 hours of effort, the private-route premium is partly wages.