Before you negotiate deal terms, accept any offer, or sign a letter of intent, there’s one question you need to be able to answer: how much of this am I actually keeping? Understanding how to calculate capital gains tax on a business sale gives you real leverage. It changes how you evaluate offers, how you compare exit options, and how you approach the overall negotiation.
The calculation is more layered than most sellers expect going in. Here’s how it actually works.
Start With Your Adjusted Basis
Capital gains tax applies to profit — the gain from a sale. That gain is the difference between what you receive and your adjusted cost basis. Your adjusted basis starts with what you originally paid for the business, adds any capital improvements made over the years, and subtracts any depreciation claimed.
If you bought a business for $1 million, made $500,000 in improvements, and claimed $300,000 in depreciation, your adjusted basis is $1.2 million. Sell for $4 million and the total gain is $2.8 million. That’s the number the tax calculation builds from.
Long-Term vs Short-Term Rates
Gains on assets held more than one year are classified as long-term capital gains and taxed federally at 0, 15, or 20 percent depending on income. Most business owners in a planned exit hit the 20 percent rate. Short-term gains — from assets held less than a year — are taxed as ordinary income at rates up to 37 percent. In most planned exits, you’re dealing with long-term gains, but the character of specific assets within the deal can still matter.
Depreciation Recapture Changes the Math
Here’s where many sellers get surprised. Depreciation previously claimed doesn’t always qualify for the long-term capital gains rate. Under Section 1245, recaptured depreciation on equipment and personal property is taxed as ordinary income — up to 37 percent federally. Under Section 1250, recaptured depreciation on real property is taxed at a maximum unrecaptured gain rate of 25 percent. Both are materially higher than the 20 percent capital gains rate most sellers anticipated paying on the full deal.
This is the primary reason the blended effective tax rate on a business sale is often much higher than the headline capital gains rate suggests.
The Net Investment Income Tax
For sellers whose modified adjusted gross income exceeds $200,000 as a single filer or $250,000 as a joint filer, the net investment income tax adds an additional 3.8 percent on top of federal capital gains. Whether it applies in a specific transaction depends on the seller’s income classification and how the deal is structured, but for most business owners completing a meaningful sale, it does apply.
State Capital Gains Taxes
Most states also tax capital gains — some at the same rate as ordinary income, others at preferential rates. High-tax states like California and New York can add 8 to 13 percent on top of federal exposure. A handful of states impose no income tax at all, which carries meaningful planning implications for sellers who have flexibility on residency before a transaction closes.
The Full Picture
Add the federal long-term capital gains rate, the recapture tax on depreciated assets, the net investment income tax if it applies, and the applicable state rate. For many sellers, the combined effective rate lands between 30 and 40 percent. On a $5 million gain, that’s $1.5 to $2 million. On a $10 million gain, it’s $3 to $4 million. These are not rounding errors — they’re the difference between what a deal looks like on paper and what the owner actually takes home.
How an ESOP Changes the Calculation
The most significant thing an ESOP can do for a C corporation seller is remove much of this calculation from the equation — or defer it indefinitely.
Under Section 1042, a qualifying seller who reinvests ESOP sale proceeds in Qualified Replacement Property pays no capital gains tax on the transaction. The gain is deferred. If the QRP is held until death, the deferred gain is eliminated permanently through a stepped-up basis for heirs.
On the company side, a 100 percent ESOP-owned S corporation pays no federal income tax going forward. The long-term economics of the business shift fundamentally — in a direction that compounds in the employees’ favor over time. Understanding how do you calculate capital gains in a standard sale makes the ESOP comparison even clearer. The numbers are not close.
MBO Ventures helps owners model the actual tax impact of a business sale in both an ESOP scenario and a traditional sale, so you can make a decision based on real numbers. Reach out at mboventures.com.