POSITION SIZE
How many lots should this trade be?
Decide the risk first; let the stop distance decide the lot size. Enter account, risk percent, entry and stop to get lots, risk amount and notional value.
Formula: lots = (balance × risk%) ÷ (|entry − stop| × value per unit per lot). Presets use common contract sizes (EUR/USD 1 lot = 100,000; gold 1 lot = 100 oz). Your broker's specification wins.