What is Capital Gains Tax
Capital gains tax is the tax owed on the profit made when you sell an asset — such as stocks, real estate, or other investments — for more than you paid for it.
Capital gains tax is the tax you pay on the profit — the capital gain — earned when you sell an asset for more than you paid for it. The asset can be a stock, bond, mutual fund, real estate, cryptocurrency, collectible, or virtually anything of value. The gain itself (not the full sale price) is what gets taxed.
Capital Gain = Sale Price − Cost Basis (what you originally paid)
Short-Term vs. Long-Term Capital Gains
The most important distinction in capital gains taxation is how long you held the asset before selling:
| Holding Period | Tax Rate |
|---|---|
| Short-term (held ≤ 1 year) | Taxed as ordinary income (10%–37% depending on tax bracket) |
| Long-term (held > 1 year) | Taxed at preferential rates (0%, 15%, or 20%) |
Holding an investment for at least one year before selling can dramatically reduce the tax owed on a gain — this is one of the most impactful and legal tax strategies available to investors.
2025 Long-Term Capital Gains Tax Rates
| Tax Rate | Single Filers | Married Filing Jointly |
|---|---|---|
| 0% | $0–$48,350 | $0–$96,700 |
| 15% | $48,351–$533,400 | $96,701–$600,050 |
| 20% | Over $533,400 | Over $600,050 |
Most middle-income investors pay the 15% long-term rate, while lower-income investors may owe 0%.
Net Investment Income Tax (NIIT)
High earners (above $200,000 single / $250,000 married) may owe an additional 3.8% Net Investment Income Tax on top of capital gains, bringing the maximum effective rate to 23.8% for long-term gains.
Capital Gains on Real Estate
When you sell a primary residence at a profit, the IRS allows a significant exclusion:
- Single filers: Up to $250,000 of gain excluded from taxes
- Married filing jointly: Up to $500,000 excluded
To qualify, you must have owned and lived in the home as your primary residence for at least 2 of the 5 years before the sale. Any gain above the exclusion is taxed at long-term capital gains rates (assuming you owned the home for more than a year).
Capital Gains in a 401(k) and Roth IRA
One of the major benefits of tax-advantaged retirement accounts is that capital gains inside them are not taxed annually. Inside a Roth IRA, investment gains are never taxed (qualified withdrawals are tax-free). Inside a traditional 401(k), gains are tax-deferred — you'll pay income tax on withdrawals, but not capital gains tax on the gains themselves. This makes these accounts especially valuable for investments expected to appreciate significantly.
Tax-Loss Harvesting
Tax-loss harvesting is the practice of intentionally selling investments at a loss to offset capital gains elsewhere in your portfolio, reducing your overall tax bill. For example, if you have a $10,000 gain and sell a losing investment for a $3,000 loss, you only owe tax on $7,000 in gains. Up to $3,000 in net losses per year can also offset ordinary income, with remaining losses carried forward to future years.
Real estate investors can defer capital gains indefinitely using a 1031 exchange — rolling the profits from one investment property into a like-kind replacement. Similarly, crypto taxes follow capital gains rules with additional complexity around staking rewards and DeFi activity.
Reporting Capital Gains
Capital gains are reported on Schedule D of your federal tax return, using information from Form 1099-B that your brokerage provides. Tax software like TurboTax automatically imports 1099-B information from major brokerages, simplifying capital gains reporting considerably.
Capital Gains and Inflation
One critique of capital gains tax is that it taxes nominal gains — including gains that merely kept pace with inflation. An asset bought for $10,000 that's now worth $20,000 after 30 years of inflation may not represent a real gain in purchasing power, yet the full $10,000 profit is subject to tax. This is an ongoing policy debate, but for practical purposes, the current tax code doesn't adjust for inflation.