Capital Gains Tax Calculator (US)

Capital Gains Tax, US Federal

When you sell an asset for more than you paid, the profit is a capital gain. The US taxes capital gains at different rates depending on how long you held the asset and your total taxable income.

Short-term vs Long-term:

2026 Long-term capital gains tax rates (single filers):

2026 Long-term capital gains tax rates (married filing jointly):

2026 Long-term capital gains tax rates (head of household):

The part nearly every calculator gets wrong. These are brackets, not a single rate picked off your total income. A long-term gain stacks on top of your ordinary income and is then sliced across the bands, so one gain can be taxed at two rates at once.

Say you are single with $40,000 of other taxable income and a $20,000 long-term gain. Your total is $60,000, which is above the $49,450 line, so it is tempting to charge 15% on the whole gain and call it $3,000. That is wrong. Your ordinary income fills the first $40,000, so the first $9,450 of the gain lands in the 0% band and only the remaining $10,550 is taxed at 15%. The real figure is $1,582.50, not $3,000.

The same thing happens at the top: a gain that straddles the 15% and 20% breakpoint is split between them, not thrown entirely into the 20% band. The calculator below shows the split whenever a gain crosses a line.

Net Investment Income Tax (NIIT): An additional 3.8% applies if your MAGI (Modified Adjusted Gross Income) exceeds:

• $200,000 (single or head of household) or $250,000 (married filing jointly)

NIIT does not care how long you held the asset. Short-term gains are net investment income too, so a high earner pays the 3.8% on top of the ordinary-income rate.

How capital gain is calculated: Capital Gain = Sale Price − Cost Basis − Selling Expenses

The cost basis is what you originally paid, including commissions and fees. Improvements to real estate also increase basis.

State taxes: This calculator covers federal only. Most states also tax capital gains. Add your state’s top rate to the federal estimate:

Washington charges a 7% capital gains tax on gains above $250K despite having no income tax. Many states do NOT distinguish long-term from short-term gains, taxing both at ordinary income rates.

Holding-period worth-waiting math. If you’re close to the 12-month line on a holding period, waiting often saves a lot. A $25,000 gain at a 24% federal bracket pays $6,000 federal short-term, but only $3,750 (15%) long-term: a $2,250 federal savings on the same gain just for crossing the one-year mark. The savings climb sharply at higher brackets: a 37% short-term gain falls to 20% (or 23.8% with NIIT) long-term.

Tax-saving tips most people miss:

• Use the 0% LTCG bracket. If you’re in a low-income year (early retirement, sabbatical, gap year, business loss year), long-term gains up to the bracket threshold are taxed at 0% federal. Sell winners and immediately re-buy to step up basis at zero cost.
• Tax-loss harvesting. Sell losing positions before year-end to offset gains. Up to $3,000 of net losses can deduct from ordinary income; excess carries forward indefinitely.
• Step-up basis at death. Assets inherited at death have their cost basis reset to market value, eliminating all unrealized capital gains for heirs. This is the single biggest tax break in the US code.
• 1031 exchange (real estate only). Defer gains on investment property by reinvesting proceeds in a like-kind property within 180 days.
• Hold one extra day past 12 months. The IRS counts from the day after purchase, so plan accordingly if you’re near the cutoff.

One case this page does not cover: rental property. If you claimed depreciation on a property, the part of the gain that matches the depreciation you took comes out first and is taxed as unrecaptured Section 1250 gain at up to 25%, not at the 0/15/20% rates above. Only what is left after that runs through the capital gains bands. Someone who took $80,000 of depreciation over the years pays 25% on that $80,000 slice before any of the lower rates apply, which is why a rental sale usually costs more than the gain alone suggests. Our 1031 exchange calculator handles that split, and defers the whole thing if you reinvest.

Important: This is an estimate for planning purposes only. Consult a tax professional for advice specific to your situation. High earners may also face the alternative minimum tax on top of the figures here.