US Capital Gains Tax Calculator

The US Capital Gains Tax Calculator is designed for investors, stock traders, crypto sellers, real estate sellers, business owners, and taxpayers who want a quick estimate of tax on a capital gain. Capital gains tax depends on sale price, cost basis, selling expenses, loss carryovers, holding period, filing status, other taxable income, and whether Net Investment Income Tax may apply. This calculator brings those inputs together to estimate net capital gain, regular capital gains tax, optional NIIT, total tax, after-tax gain, and effective tax rate.

Capital gain starts with the difference between what you receive from a sale and your adjusted basis. In this simplified calculator, sale price is reduced by cost basis and selling expenses to estimate realized gain before losses. If the user enters a capital loss carryover, the calculator subtracts that loss from the realized gain to estimate net capital gain. If the result is negative or zero, the calculator shows no taxable capital gain in this simplified estimate.

Holding period is one of the most important capital gains tax factors. A short-term capital gain generally applies when an asset is held for one year or less, and it is usually taxed at ordinary income tax rates. A long-term capital gain generally applies when an asset is held for more than one year, and it may receive preferential long-term capital gains rates. This calculator lets users select short-term or long-term treatment and applies different logic for each holding period.

For short-term gains, the calculator estimates the tax by comparing ordinary federal income tax with and without the short-term gain. This approach helps approximate how much additional ordinary tax is caused by the gain. Short-term gain can be expensive for higher-income taxpayers because the gain stacks on top of existing income. A taxpayer already in a higher ordinary bracket may see a higher tax cost on a short-term sale than on a similar long-term sale.

For long-term gains, the calculator uses long-term capital gains brackets from the shared US tax-rate file. Long-term gains are stacked on top of other taxable income because the rate depends on the taxpayer’s overall income level. A taxpayer with low other taxable income may have some long-term gain taxed at 0%, while a higher-income taxpayer may have gain taxed at 15% or 20%. The calculator also shows applied tax bands so users can see how much gain falls into each bracket.

Other taxable income is important because capital gains brackets do not operate in isolation. If a taxpayer has wages, business income, retirement income, interest income, or other taxable income, that income can push capital gains into a higher bracket. This is why the calculator asks for other taxable income before the capital gain. Without that input, the estimate would not reflect how income stacking affects long-term capital gains tax.

Selling expenses can reduce the gain in this simplified estimate. Examples may include brokerage commissions, closing costs, transaction fees, or other direct selling expenses. Cost basis may include original purchase cost plus certain adjustments, depending on the asset. Real estate basis can involve improvements, depreciation, and other adjustments. Stock and crypto basis can involve purchase price, fees, splits, transfers, and lot selection. This calculator uses the cost basis amount entered by the user and does not verify basis rules.

Capital loss carryovers can also affect the estimate. A capital loss carryover may offset capital gains, reducing taxable gain. This calculator lets users enter a capital loss carryover amount and subtracts it from the realized gain. It does not apply all capital loss limitation rules or ordinary income offset rules. Users with large losses, wash sales, carryovers, or multiple transactions should verify final treatment with tax software or a qualified tax professional.

The calculator includes an optional Net Investment Income Tax estimate. NIIT can apply to certain investment income for higher-income taxpayers when modified adjusted gross income exceeds the applicable threshold. This calculator uses a simplified method by applying 3.8% to the smaller of the net capital gain or the amount by which simplified income exceeds the threshold. Actual NIIT can require more detailed Form 8960 calculations and may include or exclude different types of income.

Many people search for capital gains tax calculator, long-term capital gains tax calculator, short-term capital gains tax calculator, stock tax calculator, crypto tax calculator, real estate capital gains calculator, investment tax calculator, capital gains rate calculator, and after-tax gain calculator. These searches usually have the same practical goal: the taxpayer wants to know how much tax may be due after selling an asset and how much gain remains after tax.

This calculator can be useful before selling an asset. An investor can compare short-term and long-term holding periods, test different sale prices, include estimated selling costs, and see whether other income pushes the gain into a higher rate band. A real estate seller can estimate a basic gain before considering exclusions or recapture. A crypto investor can estimate taxable gain from a sale. A business owner can use it for a simplified capital asset sale estimate.

This is a simplified capital gains tax estimator, not a full tax return calculation. Actual tax can differ because of qualified dividends, capital losses, wash sales, installment sales, real estate exclusions, depreciation recapture, collectibles rates, section 1250 gain, business asset rules, crypto lot selection, state taxes, NIIT details, AMT, and complete IRS return calculations. Use this tool for planning, then verify final tax with IRS guidance, tax software, or a qualified tax professional.