Capital Gains Tax Calculator (2026)
Capital gains stack on top of your other income, so the rate you pay depends on both the gain and your taxable income. Enter both below to see federal tax on the gain at 2026 rates, including the 3.8% Net Investment Income Tax where it applies.
| Tax on gain | $0 |
| Net Investment Income Tax (3.8%) | $0 |
| After-tax proceeds | $0 |
| Effective rate on this gain | 0% |
2026 federal brackets from IRS Rev. Proc. 2025-32, verified June 10, 2026. Estimates only: assumes modified AGI roughly equals taxable income plus the gain for the NIIT test, and excludes state taxes, collectibles (28% max), and depreciation recapture (25% max).
About this estimate
The core of the calculation is stacking. Your capital gain sits on top of your other taxable income, so the calculator taxes only the slice between your income and your income plus the gain — long-term gains against the 2026 breakpoints of $49,450 and $545,500 for single filers ($98,900 and $613,700 married filing jointly), and short-term gains against the ordinary 10%-37% brackets. That is why a single gain can be taxed at two rates at once, and why the same gain costs more in a high-income year. "Taxable income" means income after your deductions — if you take the standard deduction, subtract it from your gross income before entering the number.
The 3.8% Net Investment Income Tax is approximated: the statute tests modified adjusted gross income against fixed thresholds ($200,000 single, $250,000 joint), and the calculator stands in taxable income plus the gain for MAGI, which is close for most wage earners but not exact. State taxes, the 28% collectibles rate, 25% unrecaptured depreciation, and the married-filing-separately and head-of-household breakpoints are out of scope. Brackets come from IRS Rev. Proc. 2025-32, with source URLs kept alongside the data in the site repository.
Frequently asked questions
What are the long-term capital gains tax rates for 2026?
For single filers, the 0% rate applies up to $49,450 of taxable income, 15% up to $545,500, and 20% above that. For married filing jointly: 0% up to $98,900, 15% up to $613,700, then 20%. High earners may also owe the 3.8% Net Investment Income Tax.
How long do I need to hold an investment for long-term rates?
More than one year. Assets sold after holding for one year or less are short-term gains, taxed at your ordinary income rates (10% to 37%) rather than the lower 0%/15%/20% long-term rates.
Can one gain be taxed at two different rates?
Yes. Capital gains stack on top of your other taxable income, so a single gain can straddle a breakpoint: the portion below the threshold is taxed at the lower rate and the portion above at the higher rate. The calculator handles this automatically.
What is the Net Investment Income Tax (NIIT)?
An additional 3.8% tax on investment income for taxpayers with modified adjusted gross income above $200,000 (single) or $250,000 (married filing jointly). The thresholds are set by statute and do not adjust for inflation, so the NIIT reaches more taxpayers each year.
Further reading: the 0% capital gains bracket — who qualifies and how gain harvesting works — plus marginal vs. effective tax rates and RSU taxes, explained if the shares you're selling came from equity compensation.