Capital Gains Tax Calculator
Capital gains tax is owed on the profit when you sell an investment for more than you paid. The amount depends on the size of the gain, how long you held the asset, and the tax rate that applies to you. This is a single-position estimate. It does not net losses, apply brackets, include state taxes, or account for your full tax situation.
Estimate tax
Adjust the assumptions. Results update in your browser only.
Informational only. The tax rate field controls the estimate.
This rate is authoritative for the estimate.
Estimated tax
$750
A 15.00% effective rate on $5,000 of gain leaves $14,250 after estimated tax.
Breakdown
- Gain or loss
- $5,000
- Net proceeds
- $14,250
- Effective rate
- 15.00%
How the Capital Gains Tax calculator works
Capital gains tax estimates the tax cost of realizing a gain. The holding-period selector is informational, while the rate you enter controls the calculation.
The calculator subtracts cost basis from sale proceeds to find the gain or loss. Positive gains are multiplied by the tax rate you enter. Losses show as negative gains and produce zero estimated tax.
gain = proceeds - cost_basis
tax = max(0, gain) x tax_rate
net_proceeds = proceeds - tax
effective_rate = tax / gain when gain is positive- Cost basis is the amount paid for the investment plus commissions and eligible adjustments.
- The tax rate input is used directly because actual rates depend on income, holding period, filing status, and current law.
- A loss produces zero estimated tax in this single-position model.
When to use it
Helpful for
- Estimating the tax drag from selling a profitable position.
- Comparing after-tax proceeds before trimming or exiting a holding.
- Checking how sensitive net proceeds are to a different assumed tax rate.
Can mislead when
- You have multiple realized gains and losses that need to be netted.
- State taxes, surtaxes, wash sales, or special tax rules apply.
- Your cost basis is incomplete or reported under a different lot method.
Common mistakes
- Using sale value as taxable income instead of only the gain above basis.
- Forgetting commissions or adjustments that change cost basis.
- Applying a long-term rate to a position held one year or less.
- Ignoring other gains and losses that may offset each other on a tax return.
Worked example
The default inputs use 10000 of cost basis, 15000 of sale proceeds, and a 15% tax rate. Gain is 5000, estimated tax is 750, net proceeds are 14250, and the effective rate on the gain is 15.00%.
| Input | Value |
|---|---|
| Gain | $5,000 |
| Tax | $750 |
| Net proceeds | $14,250 |
| Effective rate | 15.00% |
Frequently asked questions
Short-term gains (assets held one year or less) are generally taxed at your ordinary income rate, while long-term gains (held more than a year) are usually taxed at lower rates. Holding longer often lowers the tax owed on the same gain.
Cost basis is generally what you paid for the investment plus commissions and certain adjustments. A higher basis means a smaller taxable gain, so tracking it accurately matters.
Yes. Capital losses offset capital gains, and net losses can typically offset a limited amount of ordinary income, with the remainder carried forward. This calculator estimates tax on a single gain and does not net multiple positions.
No. It is an estimate using the rate you enter. Actual tax depends on your full situation and current law, so confirm with a tax professional or official IRS guidance.
Find potential replacements
Use the screener to compare alternatives before realizing a taxable gain.