Capital Gains Calculator

Basis usually starts with what you paid, but the tax figure is adjusted basis—not always the purchase price shown on a statement. Certain acquisition costs and improvements can increase basis, while depreciation, casualty adjustments, returns of capital and other items can reduce it. IRS Publication 551 explains the rules. Enter the basis that applies when the asset is sold, and keep records supporting it.

A gain on a conventional capital asset held one year or less is generally short term and taxed at ordinary federal income-tax rates. A gain on an asset held more than one year is generally long term and may use the 0%, 15% or 20% maximum rates. Holding-period rules have exceptions, so confirm the dates and asset type before relying on the estimate.

The IRS capital-gain worksheet starts with total taxable income from Form 1040, after deductions, and that line already includes the taxable gain. The calculator then backs the gain out to find the ordinary-income layer beneath it. Entering income before the gain would stack the gain twice and can put it in the wrong rate band.

It is not a separate allowance applied to every gain. Long-term gain stacks above other taxable income. Only the part fitting between that ordinary-income layer and the 2026 zero-rate ceiling is taxed at 0%; the rest can spill into the 15% and 20% bands. The calculator shows each slice separately.

This calculator shows the loss and the statutory maximum that might offset other income: generally $3,000, or $1,500 if married filing separately. It does not calculate an exact deduction or carryover because Schedule D first nets all current-year short- and long-term gains and losses and then applies prior carryovers. One isolated sale is not enough to reproduce that return-wide calculation.

No. The estimate covers regular U.S. federal individual income tax attributable to the modeled sale. It excludes the 3.8% net investment income tax, state and local tax, alternative minimum tax, and special rates for collectibles or unrecaptured section 1250 gain. Those can materially increase the real tax.

A real return can include other gains and losses, loss carryovers, qualified dividends, special-rate assets, wash-sale adjustments, the home-sale exclusion, net investment income tax, credits and alternative minimum tax. The IRS worksheet also compares preferential tax with regular tax and uses the lower result. This focused estimate models one conventional investment sale and cannot replace the complete return.