Stock Profit Calculator (with fees and taxes)

Understanding the stock profit calculator — concept and principle

This calculator works out the profit or loss on a stock trade after commissions, fixed fees and taxes. It also gives the return on the money invested, the profit per share and the break-even sell price.

After 0.015% commissions on both trades, 100 shares bought at $52.40 and sold at $61.75 net $933.29.

How it is calculated

Purchase cost = buy price × shares + buy commission (% of the purchase) + fixed fee.
Sale proceeds = sell price × shares − sell commission − fixed fee − any tax on the sale amount (such as a securities transaction tax).
Gain before tax = proceeds − purchase cost; capital-gains tax applies only to a positive gain.
Return = net profit ÷ purchase cost.
Break-even price = the sell price at which net profit is zero before gains tax.

The principle

A trade only makes money if the sale covers what you paid plus every cost along the way. Percentage commissions grow with the trade size, fixed fees matter more for small trades, and a transaction tax on the sale reduces proceeds whether you gain or lose. The break-even price tells you how far the share must rise just to recover costs.

Worked example

Default inputs: buy 52.40 USD, sell 61.75 USD, 100 shares, commission 0.015% each way, no fixed fee or taxes.

Purchase cost = 5,240 + 0.015% × 5,240 ≈ 5,240.79 USD.
Sale proceeds shown = 61.75 × 100 = 6,175.00 USD; the sell commission is 0.93 USD.
Fees and taxes paid = 0.79 + 0.93 ≈ 1.71 USD.
Net profit = 6,175.00 − 0.93 − 5,240.79 ≈ 933.29 USD, or 9.33 USD per share.
Return = 933.29 ÷ 5,240.79 ≈ 17.81%; break-even sell price ≈ 52.42 USD.

Each point is the calculator re-run with only “Sell price per share” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Sell price per share	Net profit
15.4	-$3,697.27
30.9	-$2,153.75
46.3	-$610.23
61.8	$933.29
77.2	$2,476.81
92.6	$4,020.32
124	$7,107.36

How to read the result

Compare the return with how long you held the shares; a 17.81% gain in one month is very different from one over five years. In markets with a securities transaction tax, such as Korea, enter that rate in the sale-tax field to see the real profit. Check how your country taxes capital gains before using the gains-tax field.

Common mistakes

Forgetting the sell-side commission and transaction tax.
Ignoring dividends received, which add to the total return.
Using the gains tax on a loss.
Comparing returns over different holding periods without annualizing.

Keep in mind: Tax rules and fees vary by country and broker. This is an estimate for information, not investment or tax advice.

Frequently asked questions

How do I calculate stock profit?

Subtract the total purchase cost from the net sale proceeds after all fees and taxes.

What is a break-even price?

The sell price at which you neither gain nor lose after costs.

Should I include dividends?

For total return, yes; add dividends received to the proceeds.

Sources: US SEC Investor.gov, "Brokerage fees" and investor education on trading costs · 증권거래세법 (증권거래세 과세 기준)

Checked 9 Nov 2026. Trade-cost arithmetic: proceeds net of commissions and transaction taxes, tax on realised gains. Use your broker’s fee schedule and your country’s tax rules for the rates.

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