Position Sizing: Risk Percent and Lot Size | Borearis
Position sizing is how you turn a risk percentage into a lot size. It is the difference between a bad week and a blown account.
Formula
Lots = (balance × risk%) ÷ (stop distance × value per price unit per lot).
Example
Balance 10,000, risk 1%, stop 50 pips on EUR/USD: risk is 100 dollars, each pip is 10 dollars per lot, so 100 ÷ (50 × 10) = 0.20 lots.
Why fixed risk
Fixed risk keeps a losing streak survivable. Increasing size after a loss is how small drawdowns become account-ending ones.
Use the tool
The position size calculator does this in one step; the ATR stop calculator sets the stop distance from volatility.
What risk percent should I use?
One percent per trade is a common starting point; professionals often use less.
Can I size by feel?
You can, but you will not know your risk until after the trade.
Educational content only, not investment advice.