Calculator Form
Use the grid below on large, medium, and mobile screens. Submit to place results above this form.
Example Data Table
These sample scenarios help you compare how reward-to-risk and break-even accuracy shift across different investing setups.
| Scenario | Direction | Entry | Stop | Target | Reward:Risk | Break-Even Win Rate | Position Size |
|---|---|---|---|---|---|---|---|
| Pullback Long | Long | 84.20 | 80.90 | 92.40 | 2.38:1 | 29.57% | 73 |
| Breakout Long | Long | 146.00 | 140.80 | 158.50 | 2.34:1 | 29.94% | 47 |
| Trend Short | Short | 212.30 | 219.40 | 198.20 | 1.94:1 | 33.96% | 34 |
| Mean Reversion Short | Short | 97.80 | 101.40 | 90.50 | 1.95:1 | 33.94% | 67 |
Formula Used
- Long risk per unit = Entry Price − Stop Loss.
- Short risk per unit = Stop Loss − Entry Price.
- Long reward per unit = Take Profit − Entry Price.
- Short reward per unit = Entry Price − Take Profit.
- Effective Risk Per Unit = Raw Risk Per Unit + Cost Per Unit.
- Effective Reward Per Unit = Raw Reward Per Unit − Cost Per Unit.
- Risk Budget = Account Size × (Risk Percent ÷ 100).
- Position Size = Floor(Risk Budget ÷ Effective Risk Per Unit).
- Reward-to-Risk Ratio = Effective Reward Per Unit ÷ Effective Risk Per Unit.
- Break-Even Win Rate = Effective Risk ÷ (Effective Risk + Effective Reward) × 100.
- Expectancy Per Unit = (Win Probability × Reward) − (Loss Probability × Risk).
- Expectancy Per Trade = Position Size × Expectancy Per Unit.
How to Use This Calculator
- Select Long when target stays above entry. Select Short when target stays below entry.
- Enter the trade entry, stop loss, and take profit levels.
- Add total account size in your own account currency.
- Choose the percentage you can safely risk on one trade.
- Enter an estimated win rate based on backtests or trading logs.
- Add round-trip cost per unit to reflect spreads, fees, and slippage.
- Press the button to show results above the form.
- Review ratio, break-even rate, expectancy, and position size before taking the trade.
Frequently Asked Questions
1. What does reward-to-risk ratio mean?
It compares expected gain with defined loss. A 2:1 setup targets two units of reward for every one unit of risk.
2. Why does break-even win rate matter?
It shows the minimum accuracy needed to avoid losing money over many similar trades. Lower break-even rates provide more room for error.
3. Should I include fees and slippage?
Yes. Ignoring trading costs can overstate reward and understate risk. Small costs can materially reduce edge on tighter setups.
4. What is expectancy per trade?
Expectancy estimates average gain or loss using your assumed win rate, reward size, and risk size. Positive expectancy suggests statistical edge.
5. Why can position size become zero?
If one unit risks more than your allowed budget, the calculator returns zero units. Lower risk per unit or increase your account budget.
6. Can I use this for stocks, crypto, or forex?
Yes. The logic is universal. Just enter values in your instrument’s price format and keep cost per unit realistic.
7. Is a higher reward-to-risk ratio always better?
No. Very high ratios often have lower hit rates. A balanced setup needs both realistic targets and sustainable win probability.
8. How often should I review my win-rate assumption?
Review it after meaningful sample sizes. Update assumptions from recent logs, strategy changes, and market regime shifts to stay realistic.