Capital gains tax on $300,000
On a $300,000 long-term gain in 2026, federal tax runs from $38,968 (single, no other income) to $56,400 (single, $250,000 income). Selling within a year can cost much more.
Calculate with my incomeFederal tax on a $300,000 gain
| Situation | Capital gains tax | NIIT (3.8%) | Total federal | Effective rate |
|---|---|---|---|---|
| Single, no other income | $35,168 | $3,800 | $38,968 | 13.0% |
| Single, $50,000 income | $42,668 | $5,700 | $48,368 | 16.1% |
| Single, $100,000 income | $45,000 | $7,600 | $52,600 | 17.5% |
| Single, $250,000 income | $45,000 | $11,400 | $56,400 | 18.8% |
| Married filing jointly, $100,000 income | $40,335 | $5,700 | $46,035 | 15.3% |
| Married filing jointly, $250,000 income | $45,000 | $11,400 | $56,400 | 18.8% |
| Single, $100,000 income, held under a year | $89,964 | $7,600 | $97,564 | 32.5% |
Long-term gains are taxed at 0%, 15% or 20% depending on where the gain lands on top of your other taxable income, after the standard deduction. The 3.8% Net Investment Income Tax applies to the part of the gain that takes your income above $200,000 (single) or $250,000 (married filing jointly). Short-term gains are taxed as ordinary income at up to 37%.
State tax comes on top in most states. See the rate for California, New York, Texas, Florida or any other state from the list on the home page.
Your details
$
Income before capital gains. The 2026 standard deduction is subtracted automatically$
Sale price minus your cost basis (what you originally paid)2026 IRS rates — Rev. Proc. 2025-32
Your tax estimate
Estimated total tax on the gain
$51,650
on a $300,000 long-term gain
Effective rate: 17.2%
83%you keep
Net gain (you keep)$248,350
Federal CGT$45,000
NIIT (3.8%)$6,650
| Capital gain | $300,000 |
| Federal long-term rate | 15.0% |
| Federal CGT | $45,000 |
| Net Investment Income Tax (3.8%) | $6,650 |
| Total federal tax | $51,650 |
| Total tax | $51,650 |
| Net gain after tax | $248,350 |
Ways to reduce this bill
- You owe the 3.8% NIIT because your income exceeds the threshold. Tax-loss harvesting other positions this year can directly offset it.
Estimate only — 2026 IRS federal rates plus approximate state top marginal rates. Consult a tax professional before acting on these numbers.