Calculate your 2026 federal capital gains tax
Capital gains are taxed very differently depending on how long you held the asset. This calculator applies the 2026 long-term rates of 0%, 15%, and 20%, treats short-term gains as ordinary income, and layers on the 3.8% Net Investment Income Tax for higher earners.
How the stacking method works
Long-term rates are determined by where the gain stacks on top of your ordinary income. The portion of the gain that falls inside each band is taxed at that band’s rate:
0% band: total income up to 48,350 single / 96,700 joint
15% band: total income up to 533,400 single / 600,050 joint
20% band: total income above those thresholdsA short-term gain is taxed as ordinary income, so its tax equals the extra ordinary tax from stacking the gain on top of your other income. On top of either, the Net Investment Income Tax is 3.8% on the lesser of the gain and the amount your income exceeds $200,000 single / $250,000 joint.
Worked examples
Example 1 — partial 0% benefit: A single filer with $35,000 of ordinary income and a $30,000 long-term gain. The 0% band runs to $48,350, so the first $13,350 of the gain ($48,350 minus $35,000) is taxed at 0%. The remaining $16,650 of the gain falls in the 15% band — tax: $16,650 × 15% = $2,498. Income is below the $200,000 NIIT threshold, so no NIIT. Total federal capital gains tax: $2,498.
Example 2 — 15% band with NIIT: A single filer with $250,000 of ordinary income and a $100,000 long-term gain. The gain stacks from $250,000 to $350,000, entirely in the 15% band — capital gains tax: $15,000. Income exceeds the $200,000 NIIT threshold by $50,000 before the gain, so NIIT applies to the full $100,000 gain: 3.8% × $100,000 = $3,800. Total: $18,800, an effective rate of 18.8% on the gain.
Example 3 — short-term gain: The same $250,000 base income with a $50,000 short-term gain (stock held under a year). The gain is added to ordinary income at $250,000, pushing $50,000 into the 35% ordinary bracket. Federal income tax on the gain: ~$17,500. NIIT (on $50,000, with income above $200,000 threshold): $1,900. Total: ~$19,400 — about 38.8% combined effective rate vs 18.8% for the same amount held long-term.
Long-term vs short-term: the holding-period difference
The tax cost of holding an asset for more than a year (long-term) versus a year or less (short-term) can be substantial at higher incomes:
| Income situation | Short-term rate | Long-term rate | Difference |
|---|---|---|---|
| Lower income (near 0% band) | 10–12% + NIIT if applies | 0% | Large |
| Middle income | 22–24% + NIIT if applies | 15% + NIIT if applies | Meaningful |
| High income (above 533k single) | 37% + 3.8% NIIT | 20% + 3.8% NIIT | Significant |
Special asset types not modelled here
This calculator applies only the standard 0/15/20 long-term rates. Some assets face different federal rates:
- Collectibles (art, coins, stamps, wine): long-term rate capped at 28%
- Unrecaptured Section 1250 gain (depreciation on real property): maximum rate of 25%
- Qualified Small Business Stock (Section 1202): up to 100% exclusion on eligible gains
State taxes also apply in most states and can add 3–13% on top. The result here is federal only.