Trading Expectancy Calculator
Turn your win rate, average win and average loss into expectancy — the average profit or loss you can expect from every single trade.
How it works
Expectancy = win rate × avg win − loss rate × avg loss · Expectancy (R) = expectancy ÷ avg loss
Expectancy is the average dollar result of a single trade once wins and losses are weighted by how often they happen. A system can win less than half the time and still be highly profitable if its winners are large relative to its losers — and a high win rate means nothing if the occasional loss is huge. Positive expectancy is the one thing every durable strategy has in common; without it, more trading only loses money faster.
Worked example
A system wins 45% of the time, making $600 on winners and losing $300 on losers. Expectancy is 0.45 × $600 − 0.55 × $300 = $270 − $165 = $105 per trade, or 0.35R. Over 100 trades that is an expected $10,500 despite winning fewer than half the trades.
Frequently asked questions
Can a strategy be profitable with a low win rate?
Yes. Trend-following systems often win only 35–45% of the time but earn far more on winners than they lose on losers, producing strong positive expectancy. Win rate alone tells you almost nothing about profitability.
What is expectancy in R?
It is expectancy divided by your average loss, expressing the edge in units of risk rather than dollars. An expectancy of 0.35R means you net about a third of your risk per trade on average, which scales with position size.
Is a positive expectancy enough to trade?
It is necessary but not sufficient. You also need enough trades for the edge to show through, position sizing that survives losing streaks, and the discipline to keep taking every valid signal.
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Educational estimate, not investment advice. Trading involves risk of loss.