Stock Profit Calculator
Enter your buy price, sell price, share count and commissions, and this calculator returns the net profit after costs, the return on the capital you actually committed, and the exact price at which the trade breaks even.
What the numbers mean
The total cost is what left your account: shares times buy price, plus commissions. That is the correct denominator for a return figure. Dividing profit by the share cost alone quietly flatters every result, and the smaller the trade the more it flatters it.
The break-even price is where you get your money back including fees. On small positions it sits noticeably above the buy price — a $2 commission on 20 shares moves break-even by 10 cents a share, which on a $5 stock is 2% you have to earn before you have earned anything.
Return is not annualised, on purpose
A 15% gain is a very different achievement over three days than over three years, and there is no honest way to annualise a single trade — the arithmetic implies you could repeat it continuously. For a return you can compare across time, use the investment return calculator, which takes a holding period and gives a CAGR.
What this leaves out
Taxes, which depend on your jurisdiction and holding period; dividends received while holding; and the difference between the price you saw and the price you got. That last one is worth measuring — slippage on a market order in a thin stock routinely costs more than the commission does. Type the price you were filled at, not the price you clicked at.
One trade tells you nothing
A profitable trade and a good decision are different things, and after the fact they look identical. The only way to separate them is to record what you expected before the fact — entry, stop, target, and why — and check the distribution later.
The cost line matters more than it looks
Across 66,465 households from 1991 to 1996, the average household turned over 75% of its portfolio a year and earned 16.4% against a 17.9% market; the most active earned 11.4%.[1] The gap was activity, and activity is what the fee field measures.
The number is the easy part
Everything above is arithmetic, and anyone opening this page gets the same answer. What no calculator can settle is whether you took the trade on these terms, or are describing — afterwards — the version of it that worked out.
That is what a trade recorder is for: the trade committed before it resolves, timestamped and sealed on the spot, on a Merkle-anchored log a stranger can check without kappi's cooperation. The plan you typed here stops being a plan you remember having. $15/month, no free tier.
Sources
Frequently asked questions
How do I calculate stock profit?
Multiply shares by the sell price to get proceeds, subtract shares times the buy price, then subtract total commissions. Divide by total cost including commissions for the percentage return.
Should commissions be included in the return calculation?
Yes. Commissions are part of the capital committed, and excluding them overstates returns — most on small positions, where fees are a large share of the total.
What is the break-even price on a stock trade?
The buy price plus commissions spread across your shares. It is the price at which selling returns exactly what you put in.
Does this calculator handle short positions?
Enter the sell (short entry) price as the buy field and the cover price as the sell field, and the sign works out. Borrow fees are not included.