Win Rate Calculator

Win rate alone doesn't tell you whether a strategy makes money — a system that wins 70% of the time can still lose steadily if each loss is bigger than each win. This calculator pairs your win rate with expectancy, the number that actually answers "is this strategy profitable?"

How do I calculate win rate and expectancy?

Win rate is simply winning trades divided by total trades. Expectancy goes a step further and weighs that rate against how big your average win and average loss actually are.

For example, 100 trades with 42 wins, an average win of $150, and an average loss of $80:

Over 100 trades at that same expectancy, the strategy's expected result is +$1,660 — a system can lose more often than it wins and still come out ahead, as long as expectancy stays positive.

Can I be profitable with a win rate under 50%?

Yes. Trend-following strategies in particular often run win rates as low as 30-40% profitably, because their winners are typically 2-4x the size of their losers. What matters is expectancy, not the win rate in isolation — a high win rate with small wins and occasional large losses can still have negative expectancy.

How many trades do I need before these numbers mean anything?

At least 100 trades is a reasonable minimum for win rate and expectancy to start reflecting a strategy's real edge rather than short-term luck; many traders prefer 200 or more before trusting the numbers. Below roughly 50 trades, results are still dominated by randomness, even for a genuinely good or genuinely bad strategy.

Two traders, the same 100 trades, opposite results

Trader A wins 60 of 100 trades, with an average win of $50 and an average loss of $100. Trader B wins only 35 of 100, with an average win of $200 and an average loss of $80.

Across 100 trades, Trader A is down $1,000 and Trader B is up $1,800. The higher win rate belongs to the trader who loses money, because the average loss is twice the average win.

The win rate you need for your payoff

The breakeven win rate follows from the size of your average win and loss:

Trader A is 6.7 points short of breakeven, while Trader B has 6.4 points of margin. If your breakeven win rate is above the win rate you actually achieve, the fix is to change the payoff or the setups, not to chase a higher win rate.

Put costs inside the averages

Spread and commission lower every win and raise every loss. Take 42 wins from 100 trades, an average win of $150 and an average loss of $80, then assume $6.00 of cost per trade:

Expectancy falls from +$16.60 to +$10.60, so costs took 36% of the edge ($6.00 / $16.60). Include them if you want the number to reflect your real account.

How many trades before the win rate is reliable

A measured win rate is an estimate with a margin of error. With a true win rate near 50%, the 95% margin is roughly plus or minus 1.96 x the square root of (0.5 x 0.5 / trades):

• 50 trades: about plus or minus 14 points, so a measured 56% could be anything from about 42% to 70%
• 100 trades: about plus or minus 10 points
• 200 trades: about plus or minus 7 points

This is why the number from a short run of trades says little. Keep logging and recompute as the sample grows.

The same maths in R-multiples

Expressing results in R, where 1R is the amount risked, removes the position size from the picture. A trader who wins 40% of trades at +2R and loses 60% at -1R has:

One more win in every 20 trades lifts the rate to 45%, and the expectancy becomes 0.45 x 2 - 0.55 = +0.35R, which is 75% higher. Small changes in win rate matter a great deal when the payoff is fixed.

Profit factor as a second view

Profit factor divides total money won by total money lost. For the two traders above:

A profit factor below 1 means the strategy loses, and above 1 means it makes money before costs. It tells the same story as expectancy from a different angle, and it is easy to check against a platform's history report.

Streaks that a good win rate still produces

A 40% win rate means 60% of trades lose, so streaks of losses are normal, not a sign that the system broke.

• 5 losses in a row: 0.6^5 = 7.8%
• 8 losses in a row: 0.6^8 = 1.7%

Any given sequence of five trades has a 7.8% chance of being all losses, so across a hundred trades a run of five will usually appear. Size positions so that a streak of that length is survivable, which the Drawdown calculator helps you check.

Check this against your trade log

Decide how you treat breakeven trades before you count, because they change the win rate. Either leave them out of the total, or include them and fold them into your average loss, so both figures describe the same set of trades. Take the averages from your platform's history, net of costs. The Risk of Ruin calculator turns the same inputs into a survival estimate, and expected value on Wikipedia covers the maths.

Conclusion

Expectancy is only as reliable as the trade history behind it — a strong number from 20 trades can reverse completely by trade 100. Keep a consistent trade log, recompute these figures periodically as that log grows, and treat the risk/reward ratio of individual setups as the other half of this picture. See the Risk/Reward Ratio calculator and a full breakdown of the trading expectancy formula.

Frequently asked questions