Capital Gains Tax Calculator
Calculate taxes on your investment gains and explore tax-loss harvesting opportunities
Investment Transactions
Ready to Calculate?
Enter your income and investment transactions, then click "Calculate" to see your capital gains analysis.
Understanding Capital Gains Tax
When you sell an investment for more than you paid, that profit is a capital gain — and how it's taxed depends heavily on how long you held the asset. The difference between short-term and long-term treatment can change your tax bill on the same dollar of profit substantially, which is why holding period is one of the simplest levers investors have to manage their tax bill.
This calculator walks through multiple transactions at once, automatically classifying each as short-term or long-term based on the dates you enter, and layers in the Net Investment Income Tax and state tax where applicable.
How This Calculator Works
Enter your annual income, filing status, and each investment transaction's purchase price, sale price, quantity, and dates. The calculator computes your holding period for each transaction, taxes short-term gains at your ordinary marginal rate and long-term gains at the 0/15/20% long-term rates for your selected tax year, adds the 3.8% NIIT if your income exceeds the threshold, and applies your state rate — showing your total tax, after-tax gain, and the savings from long-term treatment.