About PositionSizeTool

What this site is

PositionSizeTool is a free position size calculator for forex, stocks and crypto. You enter your account balance, the percentage or fixed amount you are willing to risk, your entry price and your stop-loss price. The page returns the number of units, lots or shares you can place so that a stop-out costs you no more than the amount you decided to risk.

The tool is built around one idea that most calculators skip: the spread and the commission belong inside the risk budget. They are money you lose the moment the trade is opened, so a size that ignores them is larger than the size your plan actually allows. This page subtracts both, then rounds the result down to the unit step your broker accepts, and shows the real worst-case loss that the rounded size produces.

Who runs it

PositionSizeTool is run by an independent developer. It is not a broker, not an exchange, not a signal service and not an investment adviser. Nothing here is investment advice, and nothing here is a recommendation to buy or sell anything.

Every calculation runs in your own browser. The numbers you type are never uploaded, never stored and never seen by anyone else. There is no account, no sign-up and no login.

How the numbers are produced

• Risk budget — your account balance multiplied by your risk percentage, or a fixed amount you type in.
• Effective stop distance — the distance between your entry and your stop, plus the spread.
• Units — (risk budget − commission) ÷ (effective stop distance × quote-to-account rate).
• Tradable size — units rounded down to your broker's minimum increment.

Broker contract specifications differ, so the unit step and contract size stay editable. If a figure matters to a live order, check it against your broker's own contract specification before you place it.