Capital Gains Tax Calculator 2025
Calculate capital gains tax on stocks, real estate, and other investments. Enter your purchase price, sale price, holding period, and filing status to see your federal long-term or short-term capital gains tax. Includes Net Investment Income Tax (NIIT) for high-income filers.
Capital Gains Tax Calculator
2025 federal capital gains tax rates
Used to determine your tax bracket and NIIT eligibility
Taxed at preferential long-term capital gains rates
Short-Term vs Long-Term Capital Gains
Short-Term (Held <1 Year)
Assets held for one year or less are classified as short-term. Per IRC §1222, short-term capital gains are taxed as ordinary income at your marginal tax rate — the same rate applied to wages and salary. For 2025, these rates range from 10% to 37% depending on your taxable income and filing status.
Long-Term (Held ≥1 Year)
Assets held for more than one year qualify for preferential tax treatment under IRC §1222. Long-term capital gains are taxed at 0%, 15%, or 20% depending on your taxable income. Most taxpayers pay 15% or less. The holding period is measured from the date of acquisition to the date of sale.
2025 Long-Term Capital Gains Tax Brackets
The tax rate on long-term capital gains depends on your total taxable income and filing status. These brackets are adjusted annually for inflation.
| Rate | Single | Married Filing Jointly |
|---|---|---|
| 0% | $0 – $48,350 | $0 – $96,700 |
| 15% | $48,351 – $533,400 | $96,701 – $600,000 |
| 20% | Over $533,400 | Over $600,000 |
Source: IRS Revenue Procedure 2024-40. These brackets apply to long-term capital gains and qualified dividends for the 2025 tax year.
Net Investment Income Tax (NIIT)
In addition to the regular capital gains tax, high-income taxpayers may be subject to the Net Investment Income Tax. Under IRC §1411, a 3.8% surtax applies to the lesser of your net investment income or the amount by which your modified adjusted gross income exceeds the threshold.
NIIT Thresholds (2025)
- Single filers$200,000
- Married filing jointly$250,000
- Married filing separately$125,000
- Head of household$200,000
How NIIT Works
If your modified adjusted gross income (MAGI) exceeds the threshold for your filing status, NIIT is calculated as 3.8% on the smaller of:
- Your net investment income (capital gains, dividends, interest, etc.)
- The amount by which your MAGI exceeds the threshold
The calculator above automatically applies NIIT when your total income exceeds the applicable threshold.
Capital Gains Tax Calculator FAQ
How is capital gains tax calculated?
Capital gains tax is calculated by first determining your total gain (sale price minus purchase price). Then, depending on how long you held the asset, the gain is taxed at either ordinary income rates (short-term) or preferential long-term capital gains rates (0%, 15%, or 20%). High-income taxpayers may also owe the 3.8% Net Investment Income Tax.
What is the difference between short-term and long-term capital gains?
Short-term capital gains apply to assets held for one year or less and are taxed at ordinary income rates (10%–37%). Long-term capital gains apply to assets held for more than one year and are taxed at lower rates (0%, 15%, or 20%). The holding period is measured from the acquisition date to the sale date.
What are the 2025 long-term capital gains tax rates?
For 2025, the long-term capital gains rates are 0% for incomes up to $48,350 (single) or $96,700 (MFJ), 15% for incomes up to $533,400 (single) or $600,000 (MFJ), and 20% for incomes above those thresholds. These brackets are adjusted annually for inflation.
Does this calculator include the Net Investment Income Tax (NIIT)?
Yes. The calculator automatically applies the 3.8% NIIT when your total income (ordinary income plus capital gains) exceeds the applicable threshold — $200,000 for single filers and $250,000 for married filing jointly. NIIT is calculated on the lesser of your capital gain or the excess over the threshold.
Are capital gains taxed differently for stocks vs. real estate?
The federal capital gains tax rates apply the same way to both stocks and real estate at the federal level. However, real estate sales may qualify for additional exclusions, such as the primary residence exclusion (§121) which allows single filers to exclude up to $250,000 of gain ($500,000 for MFJ) on the sale of a primary home.
What is the 0% capital gains tax rate and who qualifies?
The 0% rate means you pay no federal capital gains tax on long-term gains. For the 2025 tax year, single filers with total taxable income up to $48,350 and married couples filing jointly with income up to $96,700 qualify for the 0% rate. Your ordinary income is counted first, so if your ordinary income fills the 0% bracket, more of your gain may be taxed at 15%.
How do I reduce my capital gains tax liability?
Common strategies include holding assets for more than one year to qualify for long-term rates, tax-loss harvesting (selling losing investments to offset gains), using tax-advantaged accounts like 401(k)s and IRAs, and timing your sales to fall in a low-income year. For real estate, the 1031 exchange allows you to defer gains by reinvesting in a like-kind property.
Is this capital gains calculator free?
Yes, completely free. No signup, no email, no limits. Enter your purchase price, sale price, holding period, filing status, and annual income to get instant results. The calculator uses current 2025 federal tax rates and brackets.
© 2025 SupaTax.ai. This capital gains tax calculator is for informational and educational purposes only. It provides estimates based on 2025 federal tax rates and does not constitute professional tax advice. Consult a qualified tax professional for advice specific to your situation. Tax laws, rates, and brackets are subject to change.