Size a position so that a stop-loss triggers no more than your maximum acceptable loss.
Position size follows from the stop distance, not from a fixed share of capital. A tight stop permits a large position at the same monetary risk, and a wide stop demands a small one. Sizing by percentage of account rather than by risk means every trade carries a different monetary risk, which is how a single position ends up dominating an account.
Stock Position Size
Shares = (account × risk per trade %) ÷ (entry price − stop price)
Shares = (account × risk per trade %) ÷ (entry price − stop price) Position size follows from the stop distance, not from a fixed share of capital. A tight stop permits a large position at the same monetary risk, and a wide stop demands a small one.
Sizing by percentage of account rather than by risk means every trade carries a different monetary risk, which is how a single position ends up dominating an account.
This calculator takes 4 inputs: Account size, Maximum risk per trade, Entry price, Stop-loss price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.