Trading Expectancy Calculator

Win rate alone doesn't determine profitability. Enter your strategy's numbers to find out whether you have a real mathematical edge.

How the FullStack Alpha expectancy calculator works

A 70% win rate sounds great until the losers are three times the size of the winners. Expectancy is the one number that tells you whether a strategy makes money over time.

What it calculates

Enter your win rate, average win, average loss and the number of trades you plan to take. The calculator returns your loss rate, expectancy per trade, the expected total over that many trades, your payoff ratio, and the smallest average win you need to break even at your current win rate.

It runs in your browser. No signup and nothing stored.

The formula

Two strategies, two answers

Strategy A wins 55% of the time, averages $300 per win and $250 per loss. Expectancy is 0.55 × $300 minus 0.45 × $250, or $52.50 per trade. Over 100 trades that is about $5,250 before costs.

Strategy B wins 70% of the time, but averages $100 per win and $300 per loss. Expectancy is 0.70 × $100 minus 0.30 × $300, or $20 lost per trade. The higher win rate loses money. That is the whole point of this calculator.

Use real numbers, not hopeful ones

Pull win rate and average win and loss from your trade journal or a backtest with at least 30 to 50 trades. Fewer than that and the result is mostly luck. Subtract commissions and slippage from your average win and add them to your average loss, or expectancy will look better than your account.

Who it is for

Anyone deciding whether a strategy deserves real money: swing traders, day traders, and anyone testing an AI trading bot's reported results. Size each trade with the FullStack Alpha swing trade planner once the edge checks out.

The FullStack Alpha Network

Four sites, one standard. Tested tools, no paid rankings.