Position size = (account × risk %) ÷ (entry price − stop price). Risk a fixed 1% of your account or less on each trade, so the distance to your stop decides how many shares or lots you take, not how confident you feel.
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Works for shares, ETFs, crypto, forex lots and futures contracts. Free, no sign-up, nothing leaves your browser. Education, not financial advice.
| Step | Rule used |
|---|---|
| Money at risk (1R) | Account × risk %. Example: £10,000 × 1% = £100. |
| Risk per unit | |Entry − stop| (converted to your account currency if needed). Example: £250 − £240 = £10. |
| Position size | 1R ÷ risk per unit, always rounded down: £100 ÷ £10 = 10 shares. Forex rounds down to 0.01 lots (1 standard lot = 100,000 units); futures to whole lots. |
| Reward : risk | |Target − entry| ÷ |entry − stop|. Break-even win rate before costs = 1 ÷ (1 + reward:risk), so 2:1 needs 33.3%. |
| Losing streaks | Account left after n losses = (1 − risk %)n; gain needed to recover = 1 ÷ that − 1. |
A wider stop means fewer shares and a tighter stop means more, but the money you lose if you are wrong stays the same. That is the whole point.
Educational tool, not financial advice. It does not recommend any trade, market or broker. Trading is risky: most retail traders lose money, and leveraged products can lose more than you deposit. Never trade money you can't afford to lose.
This tool puts a few of the named techniques from Chart Edge to work. Each line says how it relates to the tool.
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Multiply your account by the percentage you are willing to lose (for example £10,000 × 1% = £100), then divide by the distance from entry to stop (£250 entry, £240 stop = £10 per share). £100 ÷ £10 = 10 shares. Round down, never up.
Never risk more than 1% of your account on a single trade, meaning the loss if your stop is hit, not the size of the position. Ten losses in a row at 1% leave about 90.4% of the account; at 10% per trade they leave about 34.9%.
A standard lot is 100,000 units of the base currency, a mini lot 10,000 and a micro lot 1,000. Divide your money at risk by the stop distance (in your account currency) to get units, then divide by 100,000 for lots. Example: risking $100 with a 50-pip stop on EUR/USD (0.0050) gives 20,000 units, or 0.20 lots.
It depends on your win rate. Before costs, 1:1 needs a win rate above 50%, 2:1 above 33.3% and 3:1 above 25% just to break even. The calculator shows the break-even win rate for your target.
No. Leverage only changes how large a position your broker lets you open. Size the trade with the same formula and ignore how much the broker allows; with leverage a small move can wipe out a large part of your account, and some products can lose more than you deposited.
India's regulator SEBI found that 93% of individual traders in equity futures and options made losses between FY22 and FY24. In the UK, firms selling CFDs to retail clients must show the percentage of their retail accounts that lose money.
The position-size, reward:risk and losing-streak numbers are arithmetic on your inputs, using the method in Chart Edge (Part 8, Risk management).