Short-Term vs Long-Term
A capital gain is the sale price minus what you paid. You owe tax only when you sell. The holding period sets the rate.
Short-term: you held the asset 1 year or less. The gain is added to your income and taxed at your ordinary rate, anywhere from 10% to 37%.
Long-term: you held it more than 1 year. The rate is 0%, 15% or 20%, depending on your taxable income.
The 2026 Long-Term Thresholds
For a single filer, the 0% rate applies while taxable income stays at or below $49,450. The 15% rate applies up to $545,500. The 20% rate applies above that. The gain itself counts as taxable income, so a large gain can push part of it into a higher zone.
Taxable income is wages minus the $16,100 standard deduction. With $40,000 of wages, taxable income is $23,900, which leaves $25,550 of room in the 0% zone. A gain up to that size is tax-free.
What a $20,000 Gain Costs at Four Incomes
The model: a single filer, wages plus one $20,000 gain, the standard deduction and federal tax only. The last column adds the 3.8% Net Investment Income Tax where it applies.
| Wages | Long-term tax | Short-term tax | Saved by waiting | Surtax (NIIT) |
|---|---|---|---|---|
| $40,000 | $0 | $2,400 | $2,400 | $0 |
| $80,000 | $3,000 | $4,400 | $1,400 | $0 |
| $150,000 | $3,000 | $4,800 | $1,800 | $0 |
| $250,000 | $3,000 | $6,400 | $3,400 | $760 |
At $40,000 the gain falls inside the 0% zone, so the long-term tax is $0. At $80,000 the gain is taxed at 15%, or $3,000. Sold short-term, the same gain costs $4,400, because it lands in the 22% bracket.
At $250,000 of wages, the long-term rate is 15% but the surtax adds $760. The surtax applies to the smaller of the gain or the amount your income exceeds $200,000.
The $80,000 Example, Step by Step
1. Taxable income before the gain. $80,000 minus the $16,100 standard deduction is $63,900.
2. Find the zone. $63,900 is above the $49,450 limit for the 0% rate and below the $545,500 limit for 15%. The whole gain is taxed at 15%.
3. Long-term tax. 15% of $20,000 is $3,000.
4. Compare short-term. Adding the gain to ordinary income raises federal tax by $4,400. Waiting past the 1-year mark saves $1,400.
How Much Gain Fits in the 0% Zone
The 0% zone is a fixed amount of room. A single filer with $40,000 of wages has $25,550 of it. A $20,000 gain fits entirely. A $40,000 gain does not: the first $25,550 is tax-free, and the rest is taxed at 15%, for $2,168 in total.
At $80,000 of wages there is no room at all, because taxable income of $63,900 is already above the $49,450 limit. That is why the same sale can cost nothing for one investor and $3,000 for another.
Common Mistakes
Selling days before the 1-year mark. The holding period runs from the day after you buy. A sale one week early can turn a $3,000 tax bill into $4,400.
Forgetting reinvested dividends. Reinvested dividends add to your cost basis. If you skip them, you report a higher gain than you earned and overpay.
Ignoring the gain's effect on other income. A large gain raises your income for the year. It can move part of your gain into the next zone and cut tax breaks that phase out with income.
Selling a winner to rebalance without a plan. A rebalance in a taxable account can create a bill. Direct new contributions to the underweight asset first, or rebalance inside a retirement account where sales are not taxed.
Ways to Lower the Bill
Hold past 1 year. If a sale is days short of the mark, check the date first.
Use losses. Losses offset gains first. If losses are larger, up to $3,000 a year reduces other income and the rest carries forward.
Time the sale. In a low-income year, such as a gap between jobs, part of your gain can land in the 0% zone.
Sell a home you lived in. If you owned and lived in the home for 2 of the last 5 years, you can exclude up to $250,000 of gain, or $500,000 for married couples filing jointly.
Gains inside a 401k or IRA are not taxed when you sell. Tax applies when you withdraw. See Roth vs traditional 401k for how that works. For the ordinary income side, see how 2026 federal tax brackets work.
What This Model Leaves Out
State tax is not included, and most states tax capital gains as ordinary income. Some assets have different rules, including collectibles and depreciated real estate. Mutual fund and ETF distributions can also create gains you did not choose. Confirm the details on your own return.
Enter your own gain, income and holding period:
Capital Gains Tax Calculator →Disclaimer: This article is for educational purposes only and does not constitute tax, legal or financial advice. Figures use 2026 federal rules and a simplified single-filer example. Your tax depends on your state, other income and the asset you sell. Consult a qualified tax professional.