Capital Gains Tax Calculator 2026
Calculate exact federal capital gains tax owed on an investment sale for 2026 — short-term, long-term, plus 3.8% Net Investment Income Tax where applicable.
2026 Long-Term Capital Gains Brackets
| Filing Status | 0% Bracket | 15% Bracket | 20% Bracket |
|---|---|---|---|
| Single | $0-$48,350 | $48,351-$533,400 | $533,401+ |
| MFJ | $0-$96,700 | $96,701-$600,050 | $600,051+ |
| HoH | $0-$64,750 | $64,751-$566,700 | $566,701+ |
| MFS | $0-$48,350 | $48,351-$300,025 | $300,026+ |
The 0% bracket is one of the most underused tax provisions in the US Code. A married couple with $96,700 of total taxable income (including the long-term gain) pays $0 federal on the gain. Strategic gain harvesting in low-income years can save tens of thousands. Source: IRS Rev. Proc. 2024-40. Last updated: May 2026.
Short-Term vs Long-Term — The 366-Day Rule
Short-term capital gains apply to assets held for one year or less — taxed at your ordinary income bracket (10%-37%). Long-term applies to assets held MORE THAN one year — taxed at the preferential 0%/15%/20% rates. The IRS holding period starts the day AFTER acquisition and ends the day of sale. Hold 365 days = short-term. Hold 366 days = long-term. The difference for high earners is the gap between 37% and 20% — significant.
Net Investment Income Tax (NIIT) — The 3.8% Surcharge
High-earning households pay an additional 3.8% Net Investment Income Tax (Section 1411) on the lesser of (1) total investment income (interest, dividends, capital gains, rental income), or (2) AGI over the threshold ($200K single, $250K MFJ, $200K HoH). This is on TOP of regular capital gains tax. A high earner selling stock for $100K gain effectively pays 23.8% federal (20% LT cap gains + 3.8% NIIT). Source: IRS Section 1411.
Strategies to Reduce Capital Gains Tax
(1) Tax-loss harvesting: sell losing positions to offset gains, up to $3,000 of net loss against ordinary income annually. (2) Hold for long-term rates: wait until 366 days held. (3) Time the sale to a low-income year: retirement, sabbatical, or year between jobs. (4) Donate appreciated stock: 100% deduction at fair value, ZERO capital gains tax — best charitable giving move. (5) Step-up basis at death: heirs inherit at fair-market value, all prior gains forgiven. (6) 1031 exchange (real estate): defer indefinitely by exchanging into like-kind property. (7) QOZ investment: defer + potentially exclude gains via Qualified Opportunity Zones.
Capital Gains Tax 2026 Calculator: State Tax Add-Ons You Can't Ignore
The federal 0%/15%/20% ladder is only half the story — most states tax long-term gains as ordinary income, and that adds 4-13.3% on top. Per the Tax Foundation state capital gains data, the highest 2026 combined rates hit California 13.3% + 20% federal = 33.3%, New York 10.9% + 20% = 30.9%, and New Jersey 10.75% + 20% = 30.75%. The nine no-income-tax states (TX, FL, WA state — but WA now has a 7% cap-gains excise tax above $270K per WA DoR, NV, TN, SD, AK, WY, NH) stay at the 20% federal ceiling. Add the 3.8% NIIT on top for high earners and the highest-combined rate can exceed 37% — a $100,000 long-term gain in California nets only $63,000 after all layered taxes. Run the calculator, then subtract your state's marginal rate from the net to see the true after-tax number.
Last updated 2026-07-01. Sources: IRS Topic 409 Capital Gains, IRS Rev. Proc. 2024-40, Tax Foundation state cap-gains data, WA DoR capital gains tax.