See the win rate required to break even at common reward-to-risk ratios, including the effect of trading costs, and the ratio required for your own win rate.
Fees + slippage as a fraction of risk, e.g. 0.1
Find the R:R you'd need
Break-even win rate
33.3%
At a 45% win rate you need at least 1 : 1.22 (before costs).
| Reward : risk | Break-even win rate |
|---|---|
| 1 : 0.5 | 66.7% |
| 1 : 0.75 | 57.1% |
| 1 : 1 | 50% |
| 1 : 1.5 | 40% |
| 1 : 2 | 33.3% |
| 1 : 2.5 | 28.6% |
| 1 : 3 | 25% |
| 1 : 4 | 20% |
| 1 : 5 | 16.7% |