How to calculate win-loss percentage
Win rate = Winning trades ÷ (Winning trades + Losing trades) × 100
Take 30 wins, 20 losses and 10 trades that closed flat. The win rate is 30 ÷ 50 = 60%. If you count the flat trades as trades that didn't win, it drops to 30 ÷ 60 = 50%. Neither is wrong, but they aren't comparable, and mixing them is a common reason a broker's win rate doesn't match your journal.
Break-even win rate for your risk-reward
Break-even win rate = Average loss ÷ (Average win + Average loss) = 1 ÷ (1 + R)
R is your reward-to-risk: average win divided by average loss. Below the break-even rate the strategy loses money; above it, it makes money before commissions. Costs push the real line a little higher.
The expectancy calculator turns the same inputs into dollars per trade, and the position size calculator keeps the average loss where you planned it.
How many trades before you trust a win rate
A win rate from a small sample is an estimate, and the calculator shows how wide it is. The range is a 95% Wilson score interval: the band your long-run win rate is likely in, given the trades so far. Here is the same 65% at three sample sizes:
- 13 of 20: 43.3% to 81.9%
- 65 of 100: 55.3% to 73.6%
- 260 of 400: 60.2% to 69.5%
At 20 trades the range is about 39 points wide, so a strategy that wins half the time could easily have produced it. At 400 trades it is about 9 points wide. That is why the calculator only calls an edge when the whole range clears break-even. The full reasoning is in how many trades before you can trust your win rate.
Track your win rate automatically
Counting wins by hand works for one strategy. The ExpectancyIQ trading dashboard calculates win rate from your imported trades, leaves break-even trades out the same way, and splits it by setup, session and instrument in the reports. More free tools are on the calculators page. This page is educational, not financial advice.