Capital Gains Tax Calculator

Estimate federal capital gains tax on investment sales

What is this? This calculator estimates how much tax you'll owe when you sell an investment — stocks, real estate, or crypto. It handles short-term gains (held <1 year, taxed as income) vs. long-term gains (held >1 year, lower tax rates), and shows the effect of tax-loss harvesting.

Who it's for: Investors selling stocks or property, people considering tax-loss harvesting to offset gains, or anyone trying to estimate taxes before making an investment exit.
Sale Details
Your Income (for bracket determination)
Tax-Loss Harvesting (offset gains with losses)
NIIT note: If MAGI + net investment income exceeds $200K (single) or $250K (married), you owe 3.8% NIIT on the lesser of net investment income or the excess over threshold.
Results
Capital Gain
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Federal Tax
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State Tax
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Total Tax
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Effective Rate
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Net Proceeds
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Estimates only. Not tax advice. Consult a CPA or use TurboTax or TaxAct for accurate filing.

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We may earn a commission if you click above. Calculator is free to use.

Frequently Asked Questions

How are capital gains taxed in 2026?

Short-term (<1 year): taxed as ordinary income (10-37%). Long-term (>1 year): 0%, 15%, or 20% depending on taxable income. High earners also pay 3.8% Net Investment Income Tax (NIIT). State taxes add more.

What is tax-loss harvesting?

Selling investments at a loss to offset capital gains and reduce taxes. You can deduct up to $3,000 in losses against ordinary income annually. The wash sale rule prevents buying the same security within 30 days before or after the sale.

How do I calculate cost basis?

Cost basis = purchase price + commissions + acquisition costs. For dividends reinvested, add the reinvested amounts. If you received stock as a gift, cost basis carries over from the giver. Inherited stock gets a step-up in basis to the date of death.

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