Capital Gains Tax Calculator 2025
This calculator estimates your 2025 federal capital gains tax on the sale of investments. Long-term capital gains (assets held more than one year) are taxed at preferential rates: 0%, 15%, or 20%, depending on your taxable income and filing status. Short-term capital gains (assets held one year or less) are taxed as ordinary income at your marginal bracket rate (10% to 37%). Enter your capital gain amount, ordinary income (wages and other non-capital-gain income), holding period, and filing status. The calculator determines your applicable capital gains rate, accounts for the interaction with ordinary income (capital gains stack on top of ordinary income for rate determination), and applies the additional Net Investment Income Tax (NIIT) of 3.8% if your modified adjusted gross income exceeds the threshold (200,000 for single, 250,000 for married filing jointly). For high earners, the combined federal top rate on long-term capital gains reaches 23.8% (20% plus 3.8% NIIT) before state taxes. The tool provides a complete tax estimate and net proceeds after all applicable federal taxes, useful for evaluating investment sales, retirement account withdrawals, and understanding the effective tax impact on investment income.
Long-term capital gains are taxed at 0%, 15%, or 20% for 2025, depending on your taxable income and filing status. Short-term gains are taxed as ordinary income (10% to 37%). An additional 3.8% Net Investment Income Tax may apply if your modified adjusted gross income exceeds $200,000 (single) or $250,000 (married filing jointly). Enter your figures below for an exact estimate.
How capital gains tax works in 2025
A capital gain arises when you sell an asset for more than its cost basis. The federal tax treatment depends on how long you held the asset. Gains on assets held for more than one year are long-term and taxed at preferential rates. Gains on assets held one year or less are short-term and added to your ordinary income.
long-term CGT = gain x applicable LT rate (0%, 15%, or 20%)
short-term CGT = gain taxed as ordinary income at graduated rates
NIIT = 3.8% x lesser of (net investment income, MAGI - threshold)
net proceeds = gain - CGT - NIIT
Your long-term rate is determined by where your total taxable income (ordinary income plus the gain) falls within the capital gains brackets. Ordinary income fills the lower brackets first; the gain is then layered on top.
2025 long-term capital gains rate thresholds
Taxable income limits below are for the long-term capital gains brackets. Income above the 0% ceiling but at or below the 15% ceiling is taxed at 15%; income above the 15% ceiling is taxed at 20%.
| Filing status | 0% up to | 15% up to | 20% above |
|---|---|---|---|
| Single | $48,350 | $533,400 | $533,400 |
| Married filing jointly | $96,700 | $600,050 | $600,050 |
| Head of household | $64,750 | $566,700 | $566,700 |
| Married filing separately | $48,350 | $300,000 | $300,000 |
Source: IRS Topic 409, verified 12 June 2026.
Worked example: long-term gain, single filer
Suppose you are a single filer with $60,000 in ordinary income and a $50,000 long-term capital gain in 2025. Total taxable income (before deductions) is $110,000.
- The 0% bracket ceiling for single filers is $48,350. Your $60,000 ordinary income already exceeds this, so none of the gain falls in the 0% band.
- The 15% bracket ceiling is $533,400. All $50,000 of the gain falls between $60,000 and $533,400, so the entire gain is taxed at 15%.
- Capital gains tax = $50,000 x 15% = $7,500.
- NIIT test: MAGI is $110,000, below the $200,000 single threshold, so no NIIT applies.
- Net proceeds after tax = $50,000 - $7,500 = $42,500.
Net Investment Income Tax (NIIT) explained
The NIIT is an additional 3.8% tax imposed by Internal Revenue Code section 1411. It applies to the lesser of your net investment income (NII) or the amount by which your modified adjusted gross income (MAGI) exceeds the applicable threshold.
| Filing status | MAGI threshold |
|---|---|
| Single / head of household | $200,000 |
| Married filing jointly | $250,000 |
| Married filing separately | $125,000 |
Capital gains count as NII. If your MAGI is $230,000 as a single filer with $50,000 in capital gains, the NIIT base is the lesser of $50,000 (NII) or $30,000 (MAGI excess over $200,000), so you pay 3.8% on $30,000 = $1,140.
Source: IRS Topic 559, verified 12 June 2026.
Capital gains tax: frequently asked questions
What is the long-term capital gains tax rate for 2025?
For 2025 there are three long-term capital gains rates: 0%, 15%, and 20%. Which rate applies depends on your taxable income and filing status. Single filers with taxable income up to $48,350 pay 0%; income between $48,350 and $533,400 is taxed at 15%; above $533,400 the rate is 20%. Married filing jointly thresholds are $96,700 and $600,050.
How are short-term capital gains taxed in 2025?
Short-term capital gains (assets held one year or less) are treated as ordinary income and taxed at the same graduated rates that apply to wages and salary, ranging from 10% to 37% depending on your total taxable income.
What is the Net Investment Income Tax (NIIT)?
The NIIT is an additional 3.8% tax on the lesser of your net investment income or the amount by which your modified adjusted gross income (MAGI) exceeds a threshold. For 2025 the threshold is $200,000 for single filers and head of household, $250,000 for married filing jointly, and $125,000 for married filing separately. Capital gains count as net investment income.
What counts as a long-term vs. short-term capital gain?
If you hold an asset for more than one year before selling it, the resulting gain is long-term. If you hold it for one year or less the gain is short-term. The holding period begins the day after you acquire the asset and ends on the day you dispose of it.
Do capital gains affect my ordinary income tax bracket?
Long-term capital gains are not added to your ordinary income for purposes of determining your ordinary income tax rate. However, capital gains do stack on top of ordinary income when determining which capital gains rate bracket applies. The calculator accounts for this by using your ordinary income as the starting point for bracket placement.
Official sources
- Capital gains rates and holding period rules: IRS Topic 409 (Capital Gains and Losses), verified 12 June 2026.
- Net Investment Income Tax thresholds and rules: IRS Topic 559, verified 12 June 2026.
- 2025 federal income tax brackets (used for short-term gains): IRS federal income tax rates and brackets, verified 12 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 12 June 2026. See our methodology. General information, not financial or tax advice.