Stock Profit and Loss Calculator

100 shares bought 12, sold 15, 20 commission: (15-12) × 100 - 20 = 280 profit. 23.3% return on 1,200 cost. Commissions eat return especially on small trades — brokerage matters.

A worked example

Try the defaults: buy price of 12, sell price of 15, shares of 100, total commissions of 20. The tool returns 280.00. You can adjust any input and the result updates as you type — no submit button, no reload. That's the real power here: seeing how sensitive the output is to one or two assumptions.

Here's a second scenario: you buy 500 shares at a price of 45, sell them at 52, and pay 125 in total commissions (entry and exit combined). The calculation runs as follows:

• Gross profit = (52 − 45) × 500 = 3,500
• Net profit = 3,500 − 125 = 3,375
• Initial investment = 45 × 500 = 22,500
• Percentage return = (3,375 ÷ 22,500) × 100 = 15.0%

In this case, commissions represent 0.56% of the gross gain, leaving the overall return relatively unscathed. The same 125 in costs on a smaller trade, by contrast, would consume a much larger slice of profit.

What moves the number most

The result responds to Buy Price, Sell Price, Shares, and Total Commissions. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

Why investors run this

Most people's intuition for compounding is wrong — not because the math is hard, but because linear thinking doesn't account for curves. Running numbers through a calculator like this one is the cheapest way to recalibrate that intuition before making an irreversible decision about contribution rate, asset mix, or retirement age.

Common scenarios where this matters

• Short-term trading: When hold periods are brief, commissions and bid-ask spreads form a larger percentage of total return, making this calculation more sensitive to cost.
• Position sizing: Traders evaluating whether to buy 100 shares or 1,000 shares can model how trade size affects the final dollar and percentage outcome.
• Entry and exit planning: Comparing two different exit prices or two different purchase prices illustrates the minimum gain needed to break even after costs.
• Broker selection: Swapping one commission figure for another shows the impact of brokerage fee structures on net returns.

What this does and does not capture

The calculator does compute the net profit or loss after subtracting all commissions from the gross gain. It expresses that outcome both in absolute currency terms and as a percentage return on your initial outlay.

The calculator does not account for taxes on gains, dividend income received during the holding period, changes in share price between purchase and sale that occur in real time (volatility), or the opportunity cost of capital tied up in the position. It treats the trade as a single transaction with a fixed entry and exit price, not a series of partial fills or adjustments.

Educational illustration

This result is for educational illustration only and models one scenario under simplified assumptions. Actual trading outcomes depend on market conditions, order execution, timing, and factors outside the scope of this tool.