Syed Waleed

Estimate the federal tax on your investment gains, short-term vs long-term. Free, no signup.

Capital Gains Tax Calculator

See what the IRS takes when you sell stocks, crypto, or property — short-term vs long-term rates, income stacking, and the 3.8% net investment income tax, in seconds.

What you sold the asset for, before fees.
What you originally paid, plus improvements and purchase costs.
Assets held over one year qualify for the lower long-term rates.
Your salary, business, and other income — it fills the lower brackets first, so it changes your capital gains rate.
Primary-home sellers may exclude up to $250,000 ($500,000 joint) of gain — see the FAQ below.
Estimated federal capital gains tax$0
Capital gain (sale price minus cost basis)$0
Taxed at 0% (long-term)$0
Taxed at 15% (long-term)$0
Taxed at 20% (long-term)$0
Taxed at ordinary rates (short-term)$0
Capital gains tax$0
3.8% net investment income tax (NIIT)$0
Total estimated federal tax$0
After-tax proceeds (sale price minus tax)$0

Estimate only — not tax advice. This calculator estimates federal capital gains tax only, using simplified 2025 federal brackets and thresholds. It does not include state tax, the primary-home exclusion, depreciation recapture, collectibles rates, wash-sale rules, or deductions. Your actual tax depends on your full return. Talk to a qualified tax professional before making a sale.

100% private

Every number is calculated in your browser. Nothing is sent to a server or stored.

No signup

No account, no email, no download — just enter your numbers and get the answer.

Free forever

Use it as often as you like, for as many sales as you are planning.

How to use this calculator

  1. 1Enter the sale and your cost

    Type the sale price and what you originally paid (your cost basis). The difference is your capital gain.

  2. 2Pick the holding period and filing status

    Choose short-term (held one year or less) or long-term (held over one year), then your tax filing status.

  3. 3Add your other income

    Enter your other taxable income. It fills the lower tax brackets first, which decides how much of your gain is taxed at 0%, 15%, or 20%.

  4. 4Read your estimate

    See the gain breakdown by rate, the 3.8% NIIT if it applies, and your total estimated federal tax.

Why use this calculator

Short-term vs long-term, side by side

Flip the holding period to see exactly how much waiting past one year saves you — often thousands of dollars on the same sale.

Real income stacking

Most simple calculators ignore your other income. This one stacks your gain on top of it, the way the IRS actually taxes it.

Includes the 3.8% NIIT

High earners owe an extra 3.8% on investment income above $200,000 single or $250,000 joint. Many calculators leave it out entirely.

All four filing statuses

Single, married filing jointly, head of household, and married filing separately, each with its own correct thresholds.

Plan the timing of a sale

Test selling this year vs next, or splitting a sale across two tax years, before you commit.

Federal rules only, clearly labeled

State capital gains taxes are not included, so the estimate stays honest about what it covers.

Frequently asked questions

What is the difference between short-term and long-term capital gains?
Short-term gains come from assets held one year or less and are taxed as ordinary income — up to 37% federally. Long-term gains come from assets held over one year and get preferential rates of 0%, 15%, or 20%, depending on your income. Holding an asset just past the one-year mark can cut the tax rate dramatically.
What are the 2025 long-term capital gains rates?
For 2025, the 0% rate applies up to $48,350 of taxable income for single filers ($96,700 joint, $64,750 head of household). The 20% rate starts at $533,400 single ($600,050 joint, $566,700 head of household). Everything in between is taxed at 15%. Your other income counts toward these thresholds, which is why this calculator asks for it.
What is the 3.8% net investment income tax (NIIT)?
The NIIT is an extra 3.8% tax on investment income — including capital gains — when your modified adjusted gross income exceeds $200,000 single, $250,000 married filing jointly, or $125,000 married filing separately. It applies to the smaller of your investment income or the amount over the threshold.
Does selling my primary home count?
It can, but most homeowners qualify for an exclusion: up to $250,000 of gain ($500,000 if married filing jointly) is tax-free if you owned and lived in the home for at least two of the last five years. This calculator does not apply that exclusion automatically — subtract it from your gain first if you qualify, or ask a tax professional.
What if I sell at a loss?
A capital loss means no capital gains tax on that sale. You can also generally use up to $3,000 of net capital losses per year ($1,500 if married filing separately) to offset ordinary income, and carry the rest forward to future years. This calculator shows a $0 tax for a loss.
Does this include state capital gains tax?
No. This is a federal estimate only. Most states tax capital gains as ordinary income, and a few states have no income tax at all. Add your state rate separately for a complete picture.
How is crypto taxed?
The IRS treats crypto as property, so the same capital gains rules apply: short-term if held one year or less, long-term if held longer. Trading one crypto for another is generally a taxable sale, even without cashing out to dollars.
Can I lower my capital gains tax?
Common legal strategies include holding assets longer than one year, harvesting losses to offset gains, spreading a large sale across two tax years, and donating appreciated assets instead of selling them. Always confirm the strategy fits your situation with a tax professional.

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