Stock Profit Calculator

Your real stock trade profit depends on more than just the price difference between buying and selling. To find your true return, you need to account for your full cost basis, which includes the purchase price of your shares plus any broker commissions or fees paid when buying.

Total Cost = (Number of Shares x Buy Price) + Buy Commission. This is the total capital you put into the trade.

Total Revenue = (Number of Shares x Sell Price) - Sell Commission. This is what you actually receive after selling and paying broker fees.

Gross Profit = Total Revenue - Total Cost. If this number is positive you have a capital gain; if negative, a capital loss. Taxes only apply to gains, and capital losses can offset gains elsewhere in your portfolio.

The IRS taxes stock profits differently depending on how long you held the asset before selling:

• Short-term capital gains (held less than 1 year) are taxed as ordinary income at your marginal rate, which ranges from 10% to 37% for 2025-2026 tax brackets.
• Long-term capital gains (held 1 year or more) qualify for preferential rates of 0%, 15%, or 20% depending on your taxable income. Most investors fall into the 15% bracket.
• Net Investment Income Tax (NIIT): High earners may owe an additional 3.8% surtax on net investment income if modified adjusted gross income exceeds $200,000 (single) or $250,000 (married filing jointly).

If you sell at a loss, you owe no capital gains tax on that trade. Losses can be used to offset other gains, and up to $3,000 of net losses per year can be deducted against ordinary income.

• Hold longer than one year: Qualifying for long-term capital gains rates can cut your tax bill nearly in half compared to short-term rates. The difference between a 37% and 15% rate on a $10,000 gain is $2,200 in savings.
• Use tax-loss harvesting: Sell losing positions to offset gains from winning trades. Just be careful of the IRS wash-sale rule, which disallows the loss if you repurchase a substantially identical security within 30 days.
• Invest through tax-advantaged accounts: Trades inside a Roth IRA grow and can be withdrawn completely tax-free in retirement. Traditional IRAs and 401(k) plans defer taxes until withdrawal, letting your gains compound without annual tax drag.
• Minimize commissions: Even small per-trade fees compound over many trades. Consider zero-commission brokers, but always evaluate execution quality and hidden costs like payment for order flow.
• Keep records: Track your cost basis, trade dates, and commissions carefully. Accurate records prevent overpaying taxes and simplify filing.