Capital gains tax calculator: how much can you realize at 0%?
The myth that costs people free money: "capital gains are always taxed." They're not. There's a 0% federal long-term capital-gains bracket — for 2026, gains that keep your taxable income under $49,450 (single) or $98,900 (joint) are taxed at zero. See how much you can realize tax-free and the tax on any gain.
Your 2026 gains
Your 0% room
Tax on the gain you entered
How the 0% bracket works & data sources
Long-term capital gains (assets held more than a year) and qualified dividends get their own preferential rates: 0%, 15%, or 20%. They stack on top of your ordinary taxable income. For 2026 the 0% rate applies while your total taxable income stays at or below $49,450 (single / MFS), $98,900 (married filing jointly), or $66,200 (head of household); the 15% rate runs up to $545,500 / $613,700 / $579,600, and 20% applies above that. Because it's measured on taxable income, your 2026 standard deduction — $16,100 single, $32,200 joint, $24,150 head of household — first reduces the ordinary income that fills the bracket, which is why a modest earner can realize a surprising amount tax-free. Deliberately realizing 0%-bracket gains to reset your cost basis is tax-gain harvesting, and unlike loss harvesting there's no wash-sale rule on gains — you can sell and rebuy the same day. A single gain can straddle 0% and 15%. This is a federal estimate; state tax may still apply.
Sources: IRS — Rev. Proc. 2025-32 (2026 rates & deduction) · IRS — Topic 409 (capital gains) · IRS — Pub. 550 (wash sales)
Frequently asked questions
Are capital gains really tax-free sometimes?
Federally, yes — long-term gains inside the 0% bracket owe no federal tax. It's one of the most under-used breaks in the code. State tax may still apply.
What's tax-gain harvesting?
Realizing long-term gains that fall in the 0% bracket on purpose, to raise your cost basis for free. Later sales are then measured from the higher basis, so you owe less. There's no wash-sale rule on gains, so you can rebuy immediately.
What about short-term gains?
Assets held a year or less are short-term and taxed at your ordinary income rate — the 0/15/20% rates don't apply. Holding past the one-year mark is what unlocks the preferential rates.
Is a 0% federal rate truly free?
The gain itself is federally untaxed, but it still raises your income for the year — which can affect ACA subsidies, Medicare IRMAA, how much of your Social Security is taxed, and state tax. Check those if you're near any threshold.