Free tool · Trading & Investing Education
Position size calculator (forex)
Works out how many lots to trade so that, if your stop-loss is hit, you lose only the percentage of your account you chose to risk.
Education only, not investment advice. Trading carries a real risk of loss. Disclaimer.
Everything is calculated in your browser. Nothing you type is sent to us or anyone else, and nothing is stored.
How it works
Amount at risk = balance × risk %. Each pip of a standard lot (100,000 units) is worth the pip value, so the stop costs stop pips × pip value per lot.
Dividing the amount at risk by that cost gives the lot size, rounded down to 0.01 lots so you never risk more than planned.
Lots = (balance × risk % ÷ 100) ÷ (stop-loss pips × pip value per standard lot)
Worked example
A 10,000 account risking 1% with a 25-pip stop on EUR/USD (pip value 10) can trade 0.40 lots (40,000 units), risking 100.
Limits
- Pip value depends on the pair and your account currency. Use your broker's figure.
- Slippage and gaps can make a real loss larger than planned. Educational tool only, not advice.
Questions
How much should I risk per trade?
Many educators suggest a small fixed percentage, often 0.5% to 2%, so that a run of losses cannot wipe out the account. The right amount is your decision, and trading always carries a risk of loss.