Trading expectancy calculator

Expectancy and profit factor

Profit factor = gross profit ÷ gross loss. With the same inputs it equals (win rate × average win) ÷ (loss rate × average loss) – 0.9 ÷ 0.55 ≈ 1.64 in the example. Above 1 the system is profitable before costs. To work from your actual sums of winners and losers instead, use the profit factor calculator.

Sample size matters

An expectancy from 12 trades says little. Edgetrail shows every metric with its sample size, so you know how much the number can be trusted – and replay lets you collect a hundred trades on historical candles before you risk money.

A worked example

Say your last 40 trades won 45% of the time, with an average win of 2.1 R and an average loss of 1 R. The expectancy is 0.45 × 2.1 − 0.55 × 1 = 0.395 R per trade. At 1% risk on a $10,000 account, 1 R is $100, so the system earned about $39.50 per trade on average. With 2.1 R winners the breakeven win rate is 1 ÷ (1 + 2.1) = 32.3%, so this system has room to spare. But 40 trades is a small sample: the guide how many trades a backtest needs shows how wide the range still is.

Glossary

The terms on this page – expectancy, win rate, average win and loss, breakeven win rate and sample size – are defined in the trading metrics glossary.

Updated: 4 November 2026