Sizing trades with the built-in position calculator
How the position sizer turns account risk and stop distance into the right contract size and leverage.
6 min read
The position sizer is the small panel inside the order form most new users skip. It is the right way to size a trade.
What it computes
You give it: account risk percent, entry price, stop price.
It returns: position size, required margin and implied leverage, exact dollar amount at risk, liquidation price.
The right order of operations
- Decide where the trade is invalidated. That is the stop.
- Set risk percent (1% is standard).
- Let the sizer compute size and leverage.
The reverse — picking size first and forcing a stop to fit — is what gets new traders blown up.
Watch the liquidation
The liquidation should always be further from entry than the stop. If it creeps close as you crank leverage, lower the leverage — do not move the stop.
Common mistakes
Forcing a tighter stop to fit a bigger position. Cranking leverage above the suggestion. Eyeballing after the first few trades and drifting to 1.5–2% per trade without realizing it.
For deeper context
Frequently asked questions
What is a sensible default risk percent?
1% per trade is the standard. New traders should consider 0.5% until they have 100+ trades of data. Above 2%, drawdown math gets unforgiving fast.
Why does the sizer suggest a specific leverage?
The sizer back-calculates leverage from your account, risk percent, and stop distance. Cranking leverage above the suggestion makes the position larger than the risk math intended.