Trading Expectancy Calculator

Expectancy is the average profit or loss you can expect per trade over a large sample, given your win rate and your average win and loss sizes. The formula is (win rate × average win) − (loss rate × average loss). A positive number means your strategy makes money over time; a negative number means it loses, no matter how disciplined you are.

Any positive expectancy is an edge, but the useful way to read it is per unit of risk (R). An expectancy of +0.3R means you net 0.3 times your risk per trade on average — over 100 trades that compounds meaningfully. The higher the R-expectancy, the fewer trades you need for your edge to overcome variance and prop firm drawdown.

Occasionally, by luck — but not repeatably. Negative expectancy means the math is against you, so even if variance lets you pass once, funded trading over many trades will grind the account down. Prop firm rules (targets, drawdown, consistency) are designed to filter out exactly this: they reward a real, positive edge and expose a negative one over time.

Expectancy from a handful of trades is mostly noise. A rough working minimum is 30–50 trades to see a signal and 100+ before you should trust the number, because a few large wins or losses distort small samples. Compute it from your real journal over as many trades as you have, and recompute as the sample grows.