Capital Gains Tax Calculator

Your capital gain is the sale proceeds minus your cost basis (what you originally paid, plus improvements or commissions). If you held the asset one year or less, the gain is taxed as ordinary income at your marginal bracket. If you held it more than one year, the gain qualifies for the preferential long-term rates of 0%, 15% or 20%, based on where the gain lands on top of your other taxable income.

The IRS draws the line at exactly one year: assets held one year or less generate short-term gains, taxed as ordinary income at your regular marginal rate (up to 37% in 2026). Assets held more than one year generate long-term gains, taxed at the much lower 0%, 15%, or 20% preferential rates — which is why holding an investment past the one-year mark before selling can significantly reduce your tax bill.

For 2026, single filers pay 0% on long-term gains up to $49,450 of total taxable income, 15% from there up to $545,500, and 20% above that. Married filing jointly: 0% up to $98,900, 15% up to $613,700, 20% above. Head of household: 0% up to $66,200, 15% up to $579,600, 20% above. These thresholds are set by IRS Revenue Procedure 2025-32.

Long-term capital gains are taxed using a 'stacking' method: your gain is treated as sitting on top of your other taxable income, and the 0/15/20% bands are measured against your TOTAL taxable income (other income plus the gain), not the gain alone. This means a large gain can push part of itself into a higher band even if your regular income alone would qualify for the 0% rate.

No. If your proceeds are less than your cost basis, you have a capital loss, and this calculator shows zero tax on it. In real tax filing, capital losses can offset capital gains and up to $3,000 ($1,500 if married filing separately) of ordinary income per year, with any excess carried forward to future years — but that offsetting and carryforward math is not modeled here; this tool estimates a single sale in isolation.

Cost basis is generally what you paid to acquire the asset, plus certain additions like capital improvements (for real estate) or brokerage commissions, minus any depreciation already claimed. A higher cost basis means a smaller taxable gain, so keeping records of your original purchase price and any qualifying additions is important for an accurate tax estimate.

No. The 3.8% NIIT is a separate federal tax that can apply on top of capital gains tax when your modified adjusted gross income exceeds $200,000 (single/HoH), $250,000 (MFJ), or $125,000 (MFS). It is out of scope for this calculator's v1 — high earners near those thresholds should factor in the additional 3.8% manually or consult a tax professional.

No, this calculator estimates federal capital gains tax only. Many states also tax capital gains as ordinary income at their own state rates (a few states, like Texas and Florida, have no state income tax at all), so your total tax bill will typically be higher than the federal figure shown here.

The core short-term/long-term and 0/15/20% mechanics are the same for stocks, mutual funds, and most real estate held for investment. However, special cases exist outside this calculator's scope: unrecaptured Section 1250 gain on depreciated real estate is capped at 25%, collectibles (art, coins) are capped at 28%, and a primary residence sale may qualify for the Section 121 exclusion (up to $250,000/$500,000 of gain tax-free) — none of which are modeled here.

The effective rate shown here is your total capital gains tax divided by the gain itself — the true blended rate you paid. Because long-term gains can span two bands (e.g. partly at 0% and partly at 15%), your effective rate is often lower than the top rate your gain reaches, similar to how ordinary income tax brackets work.

Two common strategies: (1) hold the asset past the one-year mark to qualify for long-term rates instead of ordinary-income rates, and (2) sell in a year when your other taxable income is lower, since long-term gains stack on top of that income and a lower base income can push more of the gain into the 0% or 15% band. Neither strategy is guaranteed to reduce tax in every situation — consult a tax professional for your specific facts.

The same short-term/long-term and preferential-rate mechanics generally apply to cryptocurrency, which the IRS treats as property. This calculator can estimate the federal tax on a crypto sale using your cost basis and proceeds, but it does not account for crypto-specific reporting nuances (e.g. multiple lots, staking income, or hard forks) — track your basis carefully and consult a tax professional for complex crypto activity.

There's no automatic withholding at closing the way there is with a paycheck (foreign sellers are a notable exception under FIRPTA, and a few states withhold at closing). Instead, the gain is reported on your federal return for the year the sale closes, and the tax is due with that return the following spring — or sooner, via estimated quarterly payments, if the gain is large enough that waiting until filing season would trigger an underpayment penalty. If the property was your primary residence, check whether the Section 121 exclusion applies before assuming the whole gain is taxable.