Long-Term Capital Gains Calculator
Estimate your US long-term capital gains tax using 2025 rates — 0%, 15%, or 20% plus NIIT.
Gain Details (US, 2025)
Enter your capital gain and income to estimate the tax owed.
About the Long-Term Capital Gains Calculator
Long-term capital gains are taxed at preferential rates — 0%, 15%, or 20% depending on your income — rather than ordinary income rates that run up to 37%. This long-term capital gains calculator estimates your tax using the 2025 brackets, so you can plan around the sale of stocks, real estate, or other assets held for more than one year.
The rate you pay depends on your total income for the year, not just the gain itself. Your other income determines which bracket the gain falls into. This makes timing important: if you expect lower income in one year than another, realising gains in the lower-income year can shift you to a lower bracket and reduce your tax. At lower incomes, some taxpayers qualify for the 0% rate, meaning long-term gains are completely tax-free.
High earners also face the additional 3.8% Net Investment Income Tax (NIIT) on the lesser of net investment income or the amount above the $200,000 (single) or $250,000 (married filing jointly) threshold. This calculator includes NIIT so the estimate reflects the full federal liability.
Looking for more options? Open the full Capital Gains Tax Calculator — it’s the same tool with every feature.
Frequently Asked Questions
What are the long-term capital gains tax rates for 2025?
For single filers in 2025: 0% on gains up to $48,350 of total income, 15% up to $533,400, and 20% above that. Married filing jointly thresholds are $96,700 and $600,050. High earners may also owe an additional 3.8% NIIT on gains above $200,000 (single) or $250,000 (MFJ) in income, potentially pushing the top rate to 23.8%.
How do I qualify for the 0% capital gains rate?
If your total taxable income (including the gain) falls below $48,350 for a single filer or $96,700 for married filing jointly in 2025, your long-term gains are taxed at 0%. This can be accessible for retirees drawing on savings with modest other income, or lower-income earners in years between jobs. Strategic realization of gains in low-income years is a common tax planning technique.
Does holding longer than a year always lower my tax?
Yes, in the US — long-term rates (0–20%) are always lower than short-term rates (ordinary income, up to 37%). Waiting one day past the one-year holding mark to sell is one of the simplest legal tax reductions available. The tradeoff is the risk of holding longer — the asset's value could fall. But purely from a tax perspective, long-term always beats short-term.
Understanding Long-Term Capital Gains Tax
Why long-term rates exist
The preferential long-term capital gains rate was created to encourage long-term investment. Short-term trading is taxed as ordinary income; long-term holding is rewarded with lower rates. The policy rationale is that capital deployed in long-term investments promotes economic growth more than frequent trading. For investors, this creates a clear incentive: whenever possible, hold assets for more than one year before selling.
Stacking gains on top of ordinary income
Capital gains are added on top of your other income when determining which bracket they fall into. If you earn $80,000 in wages and realize $100,000 in long-term gains, the gains sit on top of the income. Some of the gains may fall in the 15% bracket (income $48,350–$533,400 for single filers in 2025), but the gains themselves are taxed at the long-term rate, not the ordinary income rate for that bracket.
Tax-loss harvesting as an offset
Capital losses directly offset capital gains before any tax is calculated. Selling losing positions to generate a capital loss is a deliberate strategy called tax-loss harvesting. A $10,000 loss in one stock can eliminate the tax on $10,000 of gains elsewhere. If losses exceed gains, up to $3,000 of the net loss can offset ordinary income per year, with remaining losses carried forward indefinitely. This makes portfolio management and tax planning inseparable for active investors.