Prop firm position size calculator
Size each trade from the room you have left today, not from your account size, so one stop-out can never fail your challenge.
Maximum position size
3.12 lots
A stop-out costs $624.00.
- Risk budget for this trade
- $625.00
- Loss if stopped out
- $624.00
Why size from your remaining room?
Classic advice says to risk 1% of the account per trade. In a prop challenge the number that matters is how far you are from the daily loss and max drawdown floors. After two losses, 1% of the account can be most of what you have left for the day.
Risking a fixed share of the remaining room (for example 20–25%) means you need several consecutive losses to hit the limit, and your size shrinks automatically on bad days.
Lot sizes are rounded down to 0.01 so the loss at the stop never exceeds your budget.