Win rate means nothing without reward-to-risk
The single most common way traders fool themselves is by chasing a high win rate. It feels like skill — being right most of the time — but being right and making money are different games. What actually decides whether a strategy survives is the pairing of two numbers: how often you win, and how big your winners are compared to your losers. Fix the reward-to-risk ratio and there is exactly one win rate that leaves you flat; win more often than that and you profit, less often and you bleed. That single threshold is what this calculator returns.
The maths is simple enough to carry in your head. If your average winner and average loser are the same size, you break even at 50% — a coin flip. Skew the winners to twice the size of the losers and the breakeven drops to about 33%, which is why trend-followers can be wrong two times out of three and still get rich. Skew it the other way — small, frequent wins against rare large losses, the classic "picking up pennies" scalp — and you might need to win 70% or 80% of the time just to tread water. Then fees take a bite out of every winner and pile onto every loser, nudging the real threshold higher than the clean textbook number.
How to use it
1. Enter your average winning trade and average losing trade as a percentage of position size (or in R — the ratio is all that matters).
2. Add the round-trip fee you pay: taker fees plus slippage for both the entry and the exit.
3. Read the breakeven win rate — the line you must beat to make money.
4. Optionally type your real win rate to see how much edge (or deficit) you're running, and scan the table to see how sensitive the threshold is to your reward-to-risk.
Common mistakes
Ignoring fees on a small-edge strategy. If your average win is 0.4% and your round-trip fee is 0.12%, fees are eating a third of every winner — the breakeven win rate is far higher than the fee-free number suggests. Measuring win rate but not average size. A win/loss count tells you nothing on its own; you need the average sizes to know if the wins pay for the losses. Letting losers run past your assumed average loss. The whole calculation assumes your losers stay near the size you entered here — one runaway loss breaks the model and the account. Confusing breakeven with a target. Breakeven is the floor, not the goal; you want a comfortable margin above it, because real-world win rates wobble.
FAQ
Do I enter percentages or dollars? Either — only the ratio between average win and average loss matters, so percentages, dollars or R-multiples all give the same breakeven win rate.
Why does the breakeven number go down as my winners get bigger? Because each win covers more losses. When a winner is worth three losers, one win in four pays for the other three trades, so a 25%-ish win rate is enough to break even before fees.
Where do I get my real win rate and average sizes? From your own trade history — export your fills and average the winners and losers separately. Feed those into the expectancy calculator to turn this threshold into an expected dollar value per trade.