US Capital Gains Tax Calculator
Calculate federal Capital Gains Tax on your investment sales. Long-term gains (held more than one year) get the preferential 0%, 15%, or 20% bracket; short-term gains are taxed at your ordinary income rate. High earners also pay a 3.8% Net Investment Income Tax. State CGT is not included — varies by state.
How is this calculated?
Long-term capital gains are stacked on top of your ordinary taxable income to determine the bracket: for single filers in 2025, 0% applies up to $48,350 combined income, 15% up to $533,400, 20% above. Short-term gains are taxed using the regular federal income-tax brackets (10/12/22/24/32/35/37%). On top of either, the Net Investment Income Tax (NIIT) is 3.8% on the lesser of (net investment income) or (MAGI minus filing-status threshold — $200k single, $250k MFJ, $125k MFS). State capital gains tax is separate; nine states have no income tax (so no state CGT either), and a handful tax LTCG at the same rate as ordinary income (e.g. California at up to 13.3%).
Frequently Asked Questions
How long is 'long-term'?
More than one year. The IRS uses your holding period: from the day after you acquired the asset to (and including) the day you sold it. Held one year or less = short-term, taxed at ordinary income rates. Held longer = long-term, taxed at the preferential 0/15/20% bands.
Can I offset gains with losses?
Yes. Net short-term losses offset short-term gains; net long-term losses offset long-term gains. Excess losses offset the other type. After that, up to $3,000 of net loss can offset ordinary income per year (single or MFJ); excess carries forward indefinitely. This calculator handles a single net gain figure — net your losses before entering.
What's the 0% LTCG bracket?
For 2025 single filers, taxable income (including the LTCG itself) up to $48,350 keeps long-term gains at 0% federal. Useful for tax-gain harvesting in low-income years (e.g. early retirement, sabbatical, fellowship). MFJ: $96,700. The 0% bracket only covers gains within it; gains pushing you over the threshold are taxed at 15%.
Is NIIT the same as Medicare tax?
No — different. The Additional Medicare Tax (0.9%) is on wages and self-employment income above $200k single/$250k MFJ. NIIT (3.8%) is on investment income (interest, dividends, capital gains, rental income) above the same thresholds. Both can apply to the same person at the same time but on different types of income.
Last updated: May 2026 · Rates sourced from IRS