Professional trading calculators
The same simple math professionals use before every trade. Everything runs in your browser — nothing is stored or sent anywhere.
📐 Position size calculator
How many units can I buy so that I lose only X% if my stop is hit?
This is planned risk, not a guaranteed maximum loss. If the market gaps or moves fast, a stop order can be filled at a worse price. Fees, spreads and financing costs are not included.
📉 Losing-streak & drawdown calculator
What happens to my account after several losses in a row — and how much do I need to recover?
Try 1% vs 10% risk with 8 losses. This is why professionals risk small.
🌱 Compound growth planner
Long-term illustration of how regular contributions and compounding add up.
✅ Pre-trade checklist
Tick every box before you click buy or sell. Your progress is saved in this browser.
Risk cheat-sheet
Loss → gain needed to recover
| Loss | Needed gain |
|---|---|
| 5% | 5.3% |
| 10% | 11.1% |
| 20% | 25% |
| 30% | 42.9% |
| 50% | 100% |
| 75% | 300% |
Reward : risk → break-even win rate
| R : R | Win rate to break even |
|---|---|
| 0.5 : 1 | 67% |
| 1 : 1 | 50% |
| 1.5 : 1 | 40% |
| 2 : 1 | 33% |
| 3 : 1 | 25% |
| 4 : 1 | 20% |
🧮 Contribution margin & break-even calculator
How much does each sale contribute, and how many sales cover your fixed costs?
Simplified model: prices without VAT, no taxes, one product, costs that stay constant. Use it for orientation only.