DollarWise

Free Capital Gains Tax Calculator

October 12, 2026 · 3 min read · By the DollarWise team

How it works

Enter what you paid per share, what you sold (or plan to sell) at, and how many shares. Pick whether the holding is short-term or long-term, set your tax rate, and see your gain or loss, the estimated tax owed, and what you actually keep after tax.

Capital Gains Tax Calculator

Estimate the tax on a stock or asset sale before you sell — gain, tax, and what you keep.

100% Free Forever No Sign-up No Credit Card Private — files never leave your browser Unlimited Use

1 Your trade

2 Holding period and tax rate

Federal long-term rates are usually 0%, 15%, or 20%; short-term gains are taxed at ordinary income rates such as 22%, 32%, or 37%. Edit the rate freely — raise it if you want to include state tax.

3 See your tax estimate

📊 Your estimated capital gains tax

🎉 Free forever. No sign-up. No credit card. No limits.

This tool runs entirely in your browser — estimate taxes on as many trades as you like.

How the math works

The taxable gain is (sell price − buy price) × shares, and the tax is simply that gain multiplied by your rate — but only when the gain is positive: tax = max(gain, 0) × rate. Net proceeds are your sale proceeds (sell price × shares) minus the tax. A loss is never taxed; in the US it can instead offset other capital gains, plus up to $3,000 per year of ordinary income, with the rest carried forward — a strategy known as tax-loss harvesting. Just mind the wash-sale rule: buying back a substantially identical asset within 30 days can disallow the loss.

Everyday uses

  • Before you sell: check the tax hit on a winning stock so the April bill never surprises you.
  • Timing a sale: compare selling now at a short-term rate versus waiting until the holding turns long-term.
  • Freelancers and active investors: size up quarterly estimated tax payments from your year-to-date trades.

Frequently asked questions

What counts as long-term? In the US, an asset held for more than one year before selling. Long-term gains get the lower preferential rates (0%, 15%, or 20% for most people); a year or less is short-term and taxed like regular income.

Do I owe tax if I sell at a loss? No. Losses owe no capital gains tax, and they can be used to offset gains elsewhere in your portfolio — and up to $3,000 a year of ordinary income — which is why investors harvest losses deliberately near year-end.

Does this include state tax or the 3.8% net investment income tax? Not automatically. High earners may also owe the 3.8% NIIT, and most states tax capital gains too. To approximate the full picture, add those percentages into the rate field before calculating.