What is position sizing?
Position sizing is choosing trade size based on account size, stop distance, and risk amount.
Tool 2
Position Size Calculator
Turn your account size and stop loss into a cleaner trade size.
Position sizing means deciding how large a trade should be before you enter. Good sizing starts with the amount you are willing to lose, not with how much you want to make.
Calculator
Example Walkthrough
A trader with a $100,000 account risking 0.5% is risking $500. If the stop is 10 points away and each point is worth $5, the estimated position size is 10 contracts, lots, shares, or units depending on the market.
Common Mistakes
- Choosing size first and stop loss second.
- Increasing size to recover losses.
- Forgetting that wider stops need smaller size.
- Risking the same amount in every market without checking point value.
Checklist Before Trading
- I know my dollar risk.
- I know my stop distance.
- I checked the instrument value.
- I am comfortable with the loss before entering.
FAQ
Why does position size matter in a prop firm challenge?
Oversized trades can hit daily loss or maximum loss rules quickly. Smaller sizing gives the trader more room to make decisions.
How much should a beginner risk per trade?
Many beginners use small risk, often under 1% per trade, while learning to follow rules and handle losing streaks.
Does a wider stop need smaller size?
Yes. If the stop is farther away, the position size usually needs to be smaller to keep the same dollar risk.
Related Tools
Next, use the Daily Loss Limit Calculator or Challenge Planner.
Source note: formula logic is stored in assets/js/calculators.js. Last updated July 2026.