FINANCIAL · CAPITAL GAINS TAX

Capital Gains Tax Calculator

Estimate your federal capital gains tax on the sale of a stock or asset — short-term vs. long-term rates, plus the 3.8% Net Investment Income Tax (NIIT) for 2026.

Sale Details
Income Context

Salary, wages, and other ordinary income — helps determine your LTCG rate tier and NIIT eligibility.

02 Result (2026)
Total Federal Tax
$7,500.00
15.00% LTCG rate
Sale proceeds$100,000.00
Cost basis$50,000.00
Taxable gain$50,000.00
Capital gains tax$7,500.00
Net proceeds (after tax)$92,500.00

Federal tax only. State capital-gains taxes are not included.

About This Calculator

Estimate your federal capital gains tax on the sale of a stock, real estate, or other asset. Enter your sale proceeds, cost basis, holding period, and filing status to see your tax owed under 2026 federal rates — including the 3.8% Net Investment Income Tax (NIIT) if applicable.

How It Works

The calculator determines your taxable gain (sale proceeds minus cost basis). Short-term gains (held 365 days or less) are taxed at ordinary income rates. Long-term gains (held more than 365 days) are taxed at preferential LTCG rates of 0%, 15%, or 20% depending on your income tier. If your modified adjusted gross income (MAGI) exceeds $200,000 (single) or $250,000 (MFJ), an additional 3.8% NIIT applies.

The Formula

Tax = gain × LTCG_rate + min(gain, MAGI − threshold) × 0.038

gain
Taxable gain = sale proceeds − cost basis
LTCG_rate
Long-term capital gains rate: 0%, 15%, or 20% based on income and filing status (2026)
MAGI
Modified adjusted gross income = ordinary income + capital gain
threshold
NIIT threshold: $200,000 (single/HoH/MFS) or $250,000 (MFJ) — not inflation-adjusted

Frequently Asked Questions

What is the difference between short-term and long-term capital gains?
Short-term gains come from assets held 365 days or less and are taxed as ordinary income. Long-term gains (held more than 365 days) qualify for lower preferential rates of 0%, 15%, or 20% for 2026.
What is the Net Investment Income Tax (NIIT)?
The NIIT is an additional 3.8% federal surtax on net investment income for taxpayers whose MAGI exceeds $200,000 (single) or $250,000 (married filing jointly). It applies on top of the standard capital gains rate, making the maximum effective rate 23.8% on long-term gains.
Are state capital gains taxes included?
No. This calculator shows federal tax only. Most states also tax capital gains, though rates and rules vary widely. Consult a tax professional for your state-specific liability.
What counts as cost basis?
Your cost basis is typically the purchase price of the asset plus any commissions, fees, or improvements (for real estate). Inherited assets use a stepped-up basis equal to fair market value at the date of death.