Capital Gains Tax Calculator

Sell an asset you have held for a year or less and the gain is taxed as ordinary income, at your marginal rate — up to 37% federally. Hold it more than a year and it becomes a long-term gain, taxed at 0%, 15%, or 20% depending on your total taxable income. The holding period runs from the day after you acquired the asset through the day you sold it.

Buy at $50,000, sell at $90,000, and the gain is $40,000. For a single filer with $90,000 of other taxable income, that whole gain sits in the 15% band, so the federal tax is $6,000 and the after-tax profit $34,000. Sold at eleven months instead, the same gain is ordinary income stacked on top of $90,000 — about $9,333 in tax. Waiting a few more weeks would have been worth $3,333.

The 0/15/20% brackets are not based on the gain alone: the gain stacks on top of your ordinary taxable income and fills whatever space is left in each band. In 2025 a single filer pays 0% on long-term gains while total taxable income stays under $48,350 and 15% up to $533,400; for married filing jointly the thresholds are $96,700 and $600,050. A large gain can therefore straddle two rates.

Cost basis includes commissions and, for property, capital improvements — a new roof adds to basis, a repainted wall generally doesn't. Reinvested dividends raise the basis of a fund position, and inherited assets are stepped up to their value at the date of death, which often erases decades of gain. Getting basis right is the most common way people overpay this tax.

State tax is separate and varies enormously — some states have no capital gains tax, others tax gains as ordinary income. Above $200,000 single or $250,000 joint in modified AGI, a further 3.8% net investment income tax applies. Special rules govern collectibles at 28%, unrecaptured depreciation on rental property at 25%, and the primary-residence exclusion of $250,000 single or $500,000 joint. Treat this as a planning estimate, not a filing figure.