Selling higher than you bought is not the same as making money
Between the purchase price and the sale price sit two transactions, each of which may carry a charge, and on a small position those charges are a larger share of the trade than most people picture. A $500 purchase with a $5 commission each way needs a 2 percent rise before the sale returns the money committed. The same $5 each way on a $50,000 position needs 0.02 percent, which is noise. The fee is identical; what changed is the base it sits on.
That is what the break-even sale price is for. It answers the only question that matters at the moment of selling something that is barely up: does this sale return more than it cost to get into. The page computes it from the fees you actually pay, so on a commission-free account it sits at the purchase price and the row is uninteresting, which is itself worth confirming rather than assuming.
Return on money committed, not return on price
There are two percentages in the output and they answer different questions. The price movement is what the shares did. The return is what you got, measured against everything you had to put up, including the commission on the way in. On a clean, fee-free trade the two match. As soon as fees or tax exist they diverge, and the second is the one that describes your position.
The denominator is money committed rather than share value, because the commission on the purchase is money you spent to hold the position and cannot get back. Some calculators leave it out and report a slightly better number. It is not a large difference on ordinary positions, and it is the correct one.
Fees and tax are not assumed, because they cannot be
Brokerage pricing has no common shape. Some providers charge nothing for ordinary share orders and make their money elsewhere; some charge a flat amount per order; some charge a percentage of the trade value with a floor; some add a per-share element on top; some charge separately for currency conversion when the share trades in another currency. Both fee fields therefore start at zero and are yours to fill in from your own contract note.
Tax is more variable still. Whether a gain is taxed at all, at what rate, whether holding for longer changes the rate, whether losses can be set against gains or against other income, and whether the account itself shelters the whole thing are decided by where you live and by what kind of account holds the shares. There is no rate this page could pick that would be right for most readers, so it picks none. Type the rate that applies to you, or leave it at zero and read the pre-tax figure. If the account is a sheltered one, zero is the correct entry.
The annualised number and how it misleads
Restating a return on a yearly basis makes two holdings of different lengths comparable, which is genuinely useful across a year or two. Over a few weeks it stops being useful and starts being theatre. A 3 percent gain in nine days annualises to over 200 percent, and the only thing that figure describes is nine days multiplied by forty.
The calculator shows the annualised figure whenever you enter a holding period and warns when the period is short. Treat it as a unit conversion rather than a rate of return, and never as an expectation. This page states no historical average, no typical return and no projection, because it has no basis for any of them; every number in the output is a consequence of a price you typed.
For the cost basis that feeds the purchase price here, the average cost per share calculator handles positions built from several purchases. For income rather than sale proceeds, the dividend calculator works from the same holding.
Questions people ask
What commission should I put in if I do not know mine?
Find out rather than guess, because the figure changes the answer most on exactly the small trades where people are least likely to check. Your broker publishes a fee schedule and every executed order produces a contract note or confirmation showing what was actually deducted; the confirmation is the reliable source since promotional rates and account tiers often differ from the headline schedule. If your account genuinely charges nothing for the order, leave both fee fields at zero, and remember that a foreign-currency trade may still carry a conversion charge that the commission line does not cover.
Why is the break-even price above the purchase price when I pay no commission?
It is not. With both fee fields at zero and no percentage fee, the break-even price equals the purchase price exactly and the row will show that. If it is showing something higher, a fee field has a value in it, or a percentage fee is set, or the tax rate is doing something unexpected. Tax does not raise the break-even price, since a sale at cost produces no gain to tax.
Does this handle a loss?
Yes. Enter a sale price below the purchase price and the result comes out negative, the return is negative, and the tax line reports that there is no gain to tax rather than applying a rate to a loss. What the page will not do is model what a loss is worth against other gains, because loss relief rules vary by country and by account type and frequently depend on what else you sold in the same period.
Can I use it for something other than shares?
For anything bought and sold as a quantity at a price, the arithmetic holds: units of a fund, a currency position, a commodity, a crypto holding. The quantity field takes decimals. What it does not model is anything with a carrying cost or a payout during the holding period, so borrowing costs, leverage, storage, and dividends or interest received while you held are all outside it. A dividend received belongs in the dividend calculator rather than in this one.