Capital Gains Tax Calculator
US federal tax on capital gains for 2026: short-term gains at ordinary rates, long-term gains at 0, 15 or 20% stacked on your other taxable income, plus the 3.8% net investment income tax.
Result…
How it's calculated
Short-term tax = tax(other + short-term) − tax(other) at ordinary rates Long-term gain stacked from (other + short-term) upward: 0% to the zero-rate amount, 15% to the 15% amount, 20% above NIIT = 3.8% × min(net investment income, MAGI − threshold) Thresholds 2026: single 49,450 / 545,500; joint 98,900 / 613,700; separate 49,450 / 306,850; head of household 66,200 / 579,600
Works out US federal tax on a capital gain for tax year 2026 the way the Qualified Dividends and Capital Gain Tax Worksheet does. Short-term gains (assets held a year or less) are taxed as ordinary income using the 2026 brackets. Long-term gains are stacked on top of your other taxable income and taxed at 0% up to the maximum zero-rate amount, 15% up to the maximum 15% amount, and 20% above, using the 2026 amounts in IRS Revenue Procedure 2025-32. The 3.8% net investment income tax is added when modified AGI is over 200,000 (single and head of household), 250,000 (joint) or 125,000 (separate), per IRS Topic 559. State and local taxes are not included.
Your numbers, step by step
About the Capital Gains Tax calculator
This capital gains tax calculator estimates the US federal tax on selling shares, funds, property or other investments in tax year 2026. Short-term gains, on assets held a year or less, are taxed at ordinary income rates. Long-term gains are stacked on top of your other taxable income and taxed at 0%, 15% or 20%, using the 2026 thresholds for your filing status from IRS Revenue Procedure 2025-32. It then adds the 3.8% net investment income tax when your modified AGI is over 200,000 (250,000 joint, 125,000 separate). The working shows how much of the gain falls in each band, so you can see why the same gain is taxed differently from one person to the next. State and local taxes on gains are not included. Amounts are US dollars.
How to use it
- Choose your “Filing status”.
- Enter your “Other taxable income”: income after your deduction, without these gains.
- Enter the “Short-term capital gain” and the “Long-term capital gain” after netting losses.
- For the 3.8% tax, add any “Other net investment income” and your “Modified adjusted gross income”, or leave it at 0 to estimate it.
- Read the total tax on the gains and the split between the bands.
Worked example
A single filer has 80,000 of other taxable income, a 5,000 short-term gain and a 30,000 long-term gain. The short-term gain is taxed at 22%: 1,100. The long-term gain sits from 85,000 to 115,000, all above the 49,450 zero-rate amount and below 545,500, so it is taxed at 15%: 4,500. Modified AGI is under 200,000, so there is no net investment income tax. The total is 5,600, 16% of the gains, leaving 29,400.
Updated
Questions people ask
How do I calculate capital gains tax on a stock sale?
Take the sale price less what you paid and the costs of buying and selling. If you held it more than a year, the gain is long-term and taxed at 0, 15 or 20% depending on where it falls on top of your other taxable income; otherwise it is taxed like wages.
What are the 2026 long-term capital gains brackets?
0% up to 49,450 of taxable income for single filers (98,900 joint, 66,200 head of household), 15% up to 545,500 (613,700 joint, 579,600 head of household, 306,850 separate) and 20% above. The IRS Rev. Proc. 2025-32 section 4.03 lists them.
When does the 3.8% net investment income tax apply?
When modified AGI is over 200,000 for single and head of household filers, 250,000 for joint filers or 125,000 for married filing separately. It is 3.8% of the smaller of your investment income and the amount over the threshold, and the thresholds are not raised for inflation.
Is a common mistake to look only at the long-term rate?
Yes. The rate depends on your other income too: a large gain can push part of itself from 0% into 15%, or from 15% into 20%, and short-term gains raise your ordinary bracket. The US income tax calculator shows the ordinary brackets.
What does this capital gains estimate leave out?
The 25% rate on unrecaptured depreciation from property, the 28% rate on collectibles, the 3,000 limit on deducting net losses, the home-sale exclusion, the alternative minimum tax and state taxes. Other countries tax gains in their own ways. For a large sale, check IRS guidance or ask a tax professional.