US Capital Gains Tax Calculator

Long-term gains (on assets held more than one year) are taxed at 0%, 15% or 20% depending on your total taxable income. The gain is 'stacked' on top of your other taxable income, and the portion falling in each band is taxed at that band's rate. A 3.8% NIIT can apply on top for higher earners.

For 2025, the 0% rate applies to taxable income up to $48,350 (single) or $96,700 (married filing jointly); the 15% rate applies up to $533,400 (single) or $600,050 (MFJ); and the 20% rate applies above those levels. The gain sits on top of your other income to determine the bands.

Long-term gains are on assets held more than one year and get the favourable 0/15/20% rates. Short-term gains (assets held a year or less) are taxed as ordinary income at your normal income-tax rates, which are usually higher. This calculator covers long-term gains.

The NIIT is an extra 3.8% tax on net investment income — including capital gains — for taxpayers whose modified adjusted gross income (MAGI) exceeds $200,000 (single) or $250,000 (married filing jointly). It applies on top of the 0/15/20% capital gains rates, and this calculator includes it.

Your long-term gain is added on top of your other taxable income. The portion of the gain that falls below the 0% ceiling is taxed at 0%, the portion in the next band at 15%, and any above the 15% ceiling at 20%. So the same gain can be taxed partly at 0% and partly at 15%, depending on your income.

Yes — if your total taxable income (including the gain) stays within the 0% band ($48,350 single / $96,700 MFJ for 2025), some or all of your long-term gain can be taxed at 0% federally. This is why timing gains in lower-income years can be valuable.

No. Only the portion of your gain that pushes your stacked income above the 15% ceiling is taxed at 20%. The rest is taxed at 0% or 15%. The calculator shows exactly how much of your gain falls in each band.

For the capital-gains brackets, yes — your long-term gain is added to your other taxable income to decide which CGT band applies. However, long-term gains are taxed at the special 0/15/20% rates, not your ordinary income-tax rates.

Enter your taxable income excluding the gain — broadly your income after deductions but before adding this capital gain. The calculator stacks the gain on top of it to work out the bands. If you are unsure, your prior-year return's taxable income line is a good guide.

No — this calculator covers federal tax only. Most US states also tax capital gains, often as ordinary income, and a few have no income tax at all. If you owe state tax, that is in addition to the federal figure shown here.

There is a special exclusion: up to $250,000 of gain on a main home ($500,000 for married couples) can be excluded if you meet the ownership and use tests. Only gain above the exclusion is taxable. This calculator does not apply the home-sale exclusion automatically — enter the taxable gain after any exclusion.

Cryptocurrency is treated as property by the IRS, so selling or exchanging it produces a capital gain or loss. Held more than a year, it is a long-term gain taxed at 0/15/20% — you can use this calculator. Held a year or less, it is short-term and taxed as ordinary income.

Yes. Capital losses offset capital gains, and up to $3,000 of net losses can offset ordinary income each year, with the rest carried forward. Enter your net gain (after losses) into the calculator for the most accurate result.

Potentially both. As a US person you report worldwide gains to the IRS; as a UK resident you may also owe UK Capital Gains Tax. The US/UK treaty and the Foreign Tax Credit work to prevent double taxation, but the interaction is complex — cross-border investors should get specialist advice.

Yes. The UK has its own Capital Gains Tax rates and annual exempt amount, and it does not recognise the US holding-period or home-sale rules. For an American in the UK, a single asset sale can produce different gain figures and tax in each country, which is exactly where cross-border planning matters.

Federal capital gains tax is generally settled with your annual return, but if the gain is large you may need to make a quarterly estimated payment to avoid underpayment penalties. The UK has its own reporting deadlines, including faster reporting for residential property gains.

Qualified dividends are taxed at the same 0/15/20% rates as long-term capital gains, so the bracket logic is similar, but this tool is built for capital gains. Tell us if you would like a dedicated qualified-dividends calculator.

It uses the official 2025 long-term capital gains breakpoints and the 3.8% NIIT and is accurate for federal long-term gains stacked on ordinary income. It does not compute state tax, the home-sale exclusion, or short-term (ordinary-rate) gains.

The calculation runs entirely in your browser and nothing is stored unless you choose to download the branded PDF report, at which point you provide your name and email so we can send it. Phone and address are optional.

Yes. Enter your name and email (phone and address optional) and we generate a TaxStone-branded PDF of your capital gains breakdown to download instantly — useful for planning a sale or sharing with an adviser.

For large gains, property sales, crypto, or any US/UK cross-border situation, a quick check can save significant tax through timing, loss harvesting, or treaty positions. Book a free 20-minute call with a TaxStone Enrolled Agent.