Trading Expectancy Calculator: What One Trade Is Worth
Expectancy is what one trade is worth on average once wins and losses are weighed together. It is the single number that says whether a strategy is worth repeating.
Expectancy is what one trade is worth on average: (win rate x average win) minus (loss rate x average loss). Positive means the approach made money over the sample you measured. This calculator returns it in R and in money, plus your break-even win rate. Ten trades prove nothing; a hundred or more starts to mean something.
Expectancy calculator
Expectancy = (win rate × average win) − (loss rate × average loss), measured in R so position sizing cannot flatter it. Costs come out of this, so measure from filled prices. A projection from a small sample is not a forecast.
The formula
Expectancy = (win rate × average win) − (loss rate × average loss). Feed it your own numbers and it returns the average result of one trade. Positive means the approach made money over the sample you measured; negative means it did not, however good any single trade felt.
The calculator shows it two ways: in R (multiples of the amount you risked) and in your account currency, so you can see both the edge and what it was worth.
Why R is the honest unit
Money amounts hide position sizing. A trader who risks 5% on winners and 1% on losers can show a positive dollar figure with a negative process. Measuring in R - where one R is the amount you planned to lose - removes that. The risk:reward calculator shows the same idea from the planning side.
Expectancy needs real trades to measure. Chart Bound gives you dozens of decisions an hour on historical charts, free, so the sample builds fast.
Play free, no signup →How big a sample do you need?
Expectancy from ten trades tells you almost nothing; a few good trades dominate it. It starts to mean something over a hundred or more trades taken the same way. Until then treat it as a first reading, and keep the sample honest by logging every trade, including the ones you would rather forget, in a journal.
Turning expectancy into a plan
A positive expectancy is not a licence to size up. Combine it with the risk of ruin calculator: the pair of them answer "is this worth repeating" and "can I survive the variance while I repeat it". Costs matter too - spread, commission and slippage come out of expectancy, so measure it from filled prices.
Frequently asked questions
What is a good expectancy?
Any reliably positive expectancy after costs is worth having, and the size of it matters less than whether the sample is large enough and honestly recorded.
What is the difference between expectancy and win rate?
Win rate is only how often you win. Expectancy weighs that against how big the wins and losses are, which is why a 35% win rate can beat a 70% one.
Should I use R or money?
R for judging the strategy, money for planning the account. The calculator shows both.
Does expectancy predict future profits?
No. It measures a past sample. Markets change, and past results do not predict future results.
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Expectancy needs real trades to measure. Chart Bound gives you dozens of decisions an hour on historical charts, free, so the sample builds fast.
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