Trading expectancy calculator

This trading expectancy calculator turns your win rate and average win and loss into expected value per trade (in R and in dollars). Enter your own numbers from a journal or a backtest.

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  • runs in your browser
Your edge

Pure arithmetic — no simulation, updates instantly.

Expectancy per trade
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A positive edge still swings. How much?Prop firm variance calculator →

Enter your numbers and press Calculate.

Trades / month
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Expectancy per trade ($)
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Expectancy per month
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Expectancy per month

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Trading expectancy comes first: pass odds and payouts start from this number

Pass probability, payout and earnings estimates all quietly assume you already know your edge.

This is the math underneath all of them. Enter your real win rate and average win and loss, and you will know whether you have an edge.

Trading expectancy assumes a constant edge and independent trades

It treats win rate and average win/loss as constants and every trade as independent — real trading has streaks, and edges drift as conditions change.

The dollar figure also assumes a fixed risk amount off the starting balance, not a compounding position size.

It says nothing about whether you survive the drawdown swings a real edge produces, or whether a firm's rules let you collect on it — that is what the pass probability calculator, the drawdown calculator and the earnings calculator are for.

Trading expectancy in practice: 45% wins at 1.8R is +0.26R a trade

Say you win 45% of your trades, your average win is 1.8R and your average loss is 1R. Expectancy = 0.45 × 1.8 − 0.55 × 1 = 0.81 − 0.55 = +0.26R per trade. Risking 1% of a $50,000 account prices 1R at $500, so that is about +$130 per trade.

At three trades a day across a 21-trading-day month, that is 63 trades — roughly +16.4R, or about +$8,190 a month at this pace, before any losing streak or a change in conditions.

Now flip one input: same 45% win rate, but average win and loss both at 1R. Expectancy drops to 0.45 × 1 − 0.55 × 1 = −0.10R — a losing system despite winning nearly half the time, because the wins are no longer big enough to cover the losses.

Run your own numbers above to see whether or not you have an edge.

Related calculators

Expectancy says whether the edge is positive. It cannot say whether the account survives long enough to collect it — that is the prop firm challenge calculator, and the spread around it is the variance calculator. The floor it runs into is the drawdown calculator, and the size that sets the distance is the risk calculator. On futures, start from the futures tick value calculator.

01

Prop Firm Challenge Calculator

Monte Carlo simulation of your real odds of passing, respecting drawdown, daily loss and the time limit. Not just profit factor.

 02

Prop Firm Variance Calculator

Same edge, 1,000 accounts. See how many pass, how many breach on a bad streak first, and how deep the drawdown gets in between.

 03

Prop Firm Drawdown Calculator

Static vs trailing drawdown. See exactly where your account gets liquidated.

Common trading expectancy questions

What is trading expectancy?
Expectancy is the average result you can expect from one trade, in units of what you risked (R). It combines your win rate with the size of your average win and average loss: expectancy = (win rate × avg win R) − (loss rate × avg loss R). A positive number means your edge makes money over enough trades; a negative number means it loses, regardless of how any single trade or week feels.
What is a good expectancy for a trading strategy?
Any expectancy above zero is a real edge — the size matters less than most traders assume, because it gets multiplied by how many trades you take. A modest +0.15R expectancy at 60 trades a month is a very different outcome than the same +0.15R at 6 trades a month. There is no universal "good" number; what matters is that it is positive and measured from real trades, not hoped for.
Why does a high win rate not guarantee positive expectancy?
Because win rate alone says nothing about size. A 70% win rate with 0.5R average wins and 2R average losses is negative expectancy (0.7 × 0.5 − 0.3 × 2 = −0.25R) despite winning most of the time — the losses are just big enough to erase every advantage the win rate provides. This calculator is built specifically to catch that.
How is expectancy different from win rate or risk/reward ratio alone?
Win rate and risk/reward (average win ÷ average loss) each describe only half the picture. Expectancy is the one number that combines both, which is why two strategies can share a win rate or a risk/reward ratio and still have completely different expectancies. It is the number that determines whether an edge is profitable.
Does this calculator account for trading costs or slippage?
No — it works from the win rate and R multiples you enter, which is where commissions and slippage should already be reflected if you are pulling these numbers from a real trading record. If you are estimating rather than measuring, build in a small haircut on your average win to stay honest.