How To Calculate Stock Profit

Stock profit is the money a trade actually makes after the broker has taken its commission. The price move is only half the story; the other half is the cost of executing the trade, which is charged on the way in and usually again on the way out.

The total cost is the number of shares multiplied by the buy price. It is the capital committed to the position and the base for the return calculation.

The total proceeds are the number of shares multiplied by the sell price. It is what the position returned when it was closed, before any fee is deducted.

Commission and fees cover the broker's charge and any regulatory or exchange levy. Many modern brokers advertise commission-free trading but still pass on a regulatory fee, a currency conversion charge or a spread, so the field should hold the true round-trip cost.

Net profit is the proceeds minus the cost minus the fees. It is the money added to the account, and it is the only figure that answers whether the trade was worth making.

Return on investment expresses the net profit as a percentage of the cost. It lets trades of different sizes be compared on a level footing and is the number most investors quote when describing performance.

The holding period affects the tax treatment in most jurisdictions. A gain held beyond a set period, often a year, is typically taxed at a lower long-term rate, while a shorter gain is taxed as ordinary income. The trade maths does not change, but the after-tax result does.

Dividends received while holding the shares are a separate source of return and are not part of the price-based profit. They should be added to the total return if the aim is to measure the whole investment rather than the trade.

Partial positions complicate the arithmetic. Selling only part of a holding means the cost has to be apportioned to the shares sold, and the remaining shares carry their own cost basis for the next calculation.

Slippage is the gap between the price a trader expected and the price actually filled. On a large order in a thinly traded stock the fill can be materially worse than the quote, which reduces the realised profit below the calculated figure.

Transaction costs weigh most heavily on small trades and frequent trading. A ten dollar round-trip fee on a five hundred dollar position is two percent, which is a large hurdle to clear before the trade breaks even.

The break-even sell price is the price at which the net profit reaches zero. Knowing it tells the investor how much the stock has to rise simply to cover the cost of the trade.

The calculator models the figures entered and nothing more. It does not know the spread, the tax treatment or any dividends received. Treat the output as the pre-tax profit on the price move and adjust for those items separately.