Position size calculator

How many shares or contracts to buy when risking a fixed fraction of the account — from entry, stop, and risk %.

Calculated in this browser. Nothing is sent anywhere.

Shares/contracts = risk amount ÷ |entry − stop|, rounded down. Currency-agnostic — for forex, express prices in the quote currency and units in lots. Not financial advice.

How to use

  1. Enter account size and risk %.
  2. Enter entry price and stop price.
  3. Read the position size and the money at risk.

What it supports

Risk amount = account × risk%; shares = risk ÷ |entry − stop|. Works for long and short entries; rejects zero-distance stops. Does not include fees, slippage, or partial fills — size down if your stop is not guaranteed. Not investment advice.

Related tools

Related guides