Exercising NSOs triggers ordinary income on the bargain element (FMV minus strike). If you hold and sell later, additional capital gain or loss accrues.
Net after-tax proceeds
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Exercise cost (cash)
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Bargain element (ordinary income)
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Tax on exercise (ordinary)
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Future capital gain at sale
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Tax on sale
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Total tax over both events
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Two taxable moments, not one
A non-qualified stock option creates a tax event the day you exercise and a second one the day you sell. That structure is what makes NSOs feel deceptively simple and then bite at filing. On exercise, the spread between the fair market value and your strike price, the bargain element, is treated as ordinary compensation income. It lands on your W-2 just like salary and is taxed at your ordinary rate. Later, when you sell the shares, any move in price after the exercise date is a capital gain or loss measured against a cost basis that now equals the full FMV at exercise. This calculator runs both events and reports the after-tax cash you walk away with.
One honest note about what the tool models. The federal layer here is income tax on the bargain element plus capital gains tax on the later sale. Payroll taxes are not folded into the total. In real life your employer also withholds Social Security and Medicare on the bargain element, so your true cash bite at exercise is a bit higher than the income-tax figure alone. Treat the total tax shown as the income and capital-gains piece, and budget separately for FICA.
Exercising 1,000 shares, then selling a year later
Use the defaults: 1,000 shares, a $5 strike, FMV of $50 at exercise, a planned sale at $80, a 32% ordinary rate, and a 15% long-term capital gains rate because you hold more than a year. Here is how the numbers fall out.
| Line | Amount |
|---|---|
| Cash to exercise (1,000 x $5) | $5,000 |
| Bargain element, ordinary income (1,000 x $45) | $45,000 |
| Income tax at 32% | $14,400 |
| Capital gain at sale (1,000 x $30) | $30,000 |
| Long-term gains tax at 15% | $4,500 |
| Total income and gains tax | $18,900 |
| Net after-tax proceeds | $56,100 |
The net is gross sale value of $80,000 minus the $5,000 exercise cost minus $18,900 in tax. Notice that the bigger tax bill by far comes at exercise, not at sale, because the bargain element is taxed at the full 32% ordinary rate while the post-exercise appreciation gets the gentler 15% long-term rate.
The paper-gain trap of exercise and hold
The single most expensive NSO mistake is exercising, holding for the long-term rate, and then watching the stock fall. You owe ordinary income tax on the bargain element in the year you exercised, calculated on the FMV that day, even if the shares are worth far less by the time you sell or by the time the bill is due. The tax is locked in at exercise; the value is not. People at pre-IPO companies have exercised into a high 409A valuation, held for the gains clock, and ended up owing tax on income they never actually realized in cash. If the only reason you are holding is to convert ordinary income into long-term gains, weigh that against the risk of paying real tax on a paper number.
This tool is for employees deciding between a same-day exercise and sell versus an exercise and hold. Toggle the holding-period dropdown to "No, taxed as ordinary income" and you will see the sale tax jump, because a sale inside one year is a short-term gain taxed at your ordinary rate rather than the long-term rate. The gap between those two outputs is the reward you are chasing by holding, and the stock-drop risk above is the price of chasing it.
Can an NSO ever qualify for long-term gains on the whole position?
No. The bargain element at exercise is always ordinary income, full stop. Only the appreciation after exercise can become a long-term gain, and only if you hold the shares more than one year from the exercise date. There is no version of an NSO where the entire spread from strike to sale gets capital-gains treatment, which is the structural difference from an incentive stock option that meets its holding periods.
What if I exercise but the company is still private and I cannot sell?
You still owe ordinary income tax on the bargain element in the exercise year, with no liquidity to pay it. This is the cash-flow squeeze that catches private-company employees. Some choose to exercise only what they can afford to cover the tax on, or wait until a tender offer or IPO provides a path to sell. Run the calculator with your shares and current 409A valuation as the FMV to size the bill before you commit cash you may not get back for years.