Capital Gains Tax Calculator (2026)

Estimate federal tax on short-term and long-term capital gains, including the 0/15/20% LTCG brackets and 3.8% NIIT awareness.

By The PiggyMath Editorial Desk Last updated August 10, 2026 ✓ Independently verified against published IRS figures

How this is calculated

Short-term gains (held ≤1 year) are taxed as ordinary income on top of your other taxable income. Long-term gains use the 2026 0/15/20% brackets (single 0% to $49,450, 15% to $545,500; MFJ 0% to $98,900, 15% to $613,700). The 3.8% Net Investment Income Tax applies to the lesser of net investment income or MAGI over $200,000 single / $250,000 MFJ.

Income & gains

Other ordinary income before std. deduction ($)Wages, SE profit, interest, etc. — before the standard deduction.

Long-term capital gains ($)

Short-term capital gains ($)

Filing status

Estimated federal tax on these gains

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Short-term tax

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Long-term tax

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NIIT 3.8%

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Effective rate on gains

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Tax on gains

Long-term vs short-term

Holding past one year usually moves stock and fund gains into preferential LTCG rates. Collectibles and unrecaptured §1250 gain have special rates this page does not model. State capital gains tax is separate.

NIIT stacks

The 3.8% NIIT is on top of the 15% or 20% LTCG rate for higher MAGI — so the top combined federal rate on LTCG is often described as 23.8%.

Frequently asked questions

What are the 2026 LTCG brackets?

For single filers: 0% up to $49,450 of taxable income, 15% up to $545,500, then 20%. For MFJ: 0% to $98,900, 15% to $613,700, then 20% (Rev. Proc. 2025-32).

When does NIIT apply?

When MAGI exceeds $200,000 (single) or $250,000 (MFJ). The 3.8% hits the lesser of net investment income or the excess over that threshold.

Are crypto gains included?

Yes in concept — crypto held over a year can be long-term. Enter the gain amounts; wash-sale and specific-ID rules are out of scope.

Sources

Every formula on this page is checked against an independent implementation before publication. How we check our math →