Capital Gains Tax Calculator 2026: How Much Can You Realize at 0%?
Capital Gains Tax Calculator (2026)
See how much of a long-term gain falls in the 0%, 15%, and 20% brackets — and how much you could realize tax-free. Long-term gains stack on top of your other taxable income.
0% gains room
$61,100
Long-term gain you can realize tax-free at this income
Tax on your gains
$0
Top rate hit: 0%
Effective rate on gains
0.0%
Blended rate across the 0/15/20% bands
How your $40,000 gain is taxed
Your taxable income before gains is $37,800; the 0% bracket runs up to $98,900 of taxable income for your filing status.
Two things this does not include: the 3.8% Net Investment Income Tax (which applies once MAGI tops $200,000 single / $250,000 joint) and state income tax. Realized gains also raise MAGI, which can trigger IRMAA Medicare surcharges two years later.
Illustrative estimate based on the figures you enter and current federal tax rules — not a calculation of your actual taxes, and not tax advice. Consult a qualified tax professional. See our full disclaimer.
TL;DR
Long-term capital gains are taxed at 0%, 15%, or 20% — and they stack on top of your other taxable income. In 2026, the 0% rate runs up to $49,450 of taxable income (single) or $98,900 (married filing jointly). If your other income leaves room under that ceiling, you can realize gains in that space and pay zero federal tax. The calculator shows exactly how much room you have.
Capital gains taxation confuses people because of one quirk: long-term gains do not sit in their own bracket. They stack on top of your ordinary income, and the rate they pay depends on where that stack lands. Per IRS Topic 409, the rates are 0%, 15%, and 20% — but the line between them is set by your total taxable income, not the size of the gain alone.
How the stacking works
Picture your taxable income as a stack of blocks. Your ordinary income — wages, pensions, taxable IRA withdrawals, the taxable part of Social Security — fills the bottom. Your long-term gains and qualified dividends sit on top. The 0% band fills first, then 15%, then 20%.
This is why two people with the same gain can owe wildly different tax. A retiree with $40,000 of ordinary taxable income and a $30,000 gain (married) stays entirely inside the 2026 $98,900 zero bracket — the gain is tax-free. A working couple with $200,000 of ordinary income pays 15% on the same $30,000 gain, because their stack starts far above the 0% ceiling.
Gains harvesting: the 0% room is use-it-or-lose-it
The most valuable number the calculator produces is your 0% room — the gain you can realize this year at no federal tax. In low-income years, especially the gap between retirement and the start of Social Security or RMDs, that room can be substantial. Deliberately realizing gains up to the ceiling — then immediately rebuying — resets your cost basis higher for free, shrinking the taxable gain on a future sale. Unlike a Roth conversion, there is no tax cost to harvesting inside the 0% band.
The room does not carry forward. Every year you leave it unused is 0%-bracket space gone for good.
Watch the two hidden costs
The 0/15/20% rate is not always the whole bill. The 3.8% Net Investment Income Tax applies once MAGI tops $200,000 (single) / $250,000 (joint), and most states tax gains as ordinary income. Just as important for retirees: a realized gain raises your MAGI, which can bump you into a higher IRMAA Medicare tier two years later. The art of gains harvesting is filling the 0% band without tripping any of those other thresholds — which is exactly where coordinating it with the rest of your withdrawal sequence pays off.
Want to harvest gains at 0% without triggering IRMAA, the NIIT, or extra Social Security taxation? Connect with a retirement advisor who can sequence it across your full plan.
Frequently Asked Questions
Long-term capital gains and qualified dividends are taxed at 0% as long as your total taxable income (including the gains) stays under $49,450 for single filers or $98,900 for married filing jointly in 2026. Above those levels the rate is 15%, and above roughly $545,500 single / $613,700 joint it is 20%.
Long-term gains do not get their own separate bracket. They stack on top of your ordinary taxable income. So if you have $70,000 of ordinary taxable income (after deductions) and the married 0% ceiling is $98,900, only about $28,900 of long-term gain fits in the 0% bracket — the rest is taxed at 15%.
It equals the 0% ceiling for your filing status minus your taxable income before gains. The calculator above computes this "0% room" for you. Realizing exactly that amount each year — sometimes called gains harvesting — can reset your cost basis higher without paying any federal tax on the gain.
Possibly. The 3.8% Net Investment Income Tax applies once your MAGI exceeds $200,000 (single) or $250,000 (joint). Many states also tax capital gains as ordinary income. And because realized gains raise your MAGI, they can push you into a higher IRMAA Medicare tier two years later.
Yes. Qualified dividends are taxed at the same 0%/15%/20% long-term capital gains rates and stack the same way. Enter them together with your long-term gains in the calculator.
Sources
Want to see how this applies to your situation? Get your free personalized retirement analysis →