One trade’s average, if the inputs hold
Expectancy is win rate times average win, minus loss rate times average loss. Loss rate is one minus the win rate. A 40% win rate, a $300 average win, and a $150 average loss is 0.40 × 300 − 0.60 × 150 = $30 a trade. A 70% win rate with a large average loss can still be negative. The page exists so the win rate is not the only number on the desk.
The inputs usually do not hold. Recalculate from a real export after you have a journal, not from the last ten trades you remember. Fees belong inside the average win and the average loss if you want the expectancy of the account rather than the expectancy of the price ticks. The futures fee calculator is the place to see a round turn before you ignore it.
Tradeify’s rules do not change this formula. They change whether you are still in the account. A positive expectancy that risks the whole trailing floor on one day is not a sizing plan. Use the position size calculator for the stop, and the firm page for the floor.