Stock Profit Calculator

Calculate your profit or loss on a stock trade, including percentage return and break-even price after commissions. Adjust the inputs below and results update instantly.

How Stock Profit is Calculated

Stock profit is the difference between what you receive when selling shares and what you paid to buy them, minus any trading costs. The formula is straightforward:

Profit = (Sell Price − Buy Price) × Shares − Total Commissions

Commissions are charged on both the buy and sell side of a trade, so the total commission cost is typically double the per-trade fee. Many modern brokers offer commission-free trading on stocks, but it is still common with full-service brokers, options trades, and international markets.

Understanding Break-Even Price

The break-even price is the minimum sell price per share needed to recover your total investment including commissions. It is calculated as:

Break-Even = Buy Price + (2 × Commission) / Shares

When you buy 100 shares at $50 with a $10 commission on each trade, your break-even price is $50.20 per share. The more shares you trade, the less impact commissions have on your break-even point. This is why commission costs matter more for small trades than large ones.

How Commissions Impact Returns

Trading commissions create a hurdle that your investment must clear before you see any profit. On a small trade of 10 shares at $50 with $10 commissions each way, you need the stock to rise by $2 per share (4%) just to break even. On 1,000 shares, that same commission only requires a $0.02 move (0.04%).

This is why frequent trading with small position sizes can erode returns significantly. Even with commission-free brokers, there are often hidden costs in the form of wider bid-ask spreads, payment for order flow, or currency conversion fees on international stocks.

When evaluating a trade, always factor in the round-trip cost — the total expense of buying and then selling the position. The percentage return shown by this calculator accounts for commissions on both sides, giving you a realistic picture of your actual return.

Percentage Return vs Absolute Profit

A $500 profit means different things depending on how much capital you deployed. Earning $500 on a $1,000 investment is a 50% return — exceptional. Earning $500 on a $100,000 investment is 0.5% — barely noticeable. Percentage return normalises your result so you can compare trades of different sizes on equal footing.

This calculator computes percentage return based on your total cost basis (shares × buy price + commission), which is the standard way to measure investment performance. If you want to understand how your stock trades contribute to your overall portfolio return, consider tracking them alongside dividends and other income using a stock portfolio tracker.

Beyond Profit: Tax Considerations

Stock profits are subject to capital gains tax in most countries. In the US, gains on stocks held for less than a year are taxed as ordinary income (up to 37%), while long-term gains (held over a year) benefit from lower rates of 0%, 15%, or 20%. In the UK, capital gains above the annual exemption are taxed at 10% or 20% depending on your income tax band.

Use our Capital Gains Tax Calculator to estimate your tax liability, or explore the Dividend Calculator to project income from dividend-paying stocks.