Free trading calculator
Position Size Calculator
Estimate how many shares fit your risk plan before entering a trade.
Position size inputs
Enter your trade details
Estimated position size
125
shares
- Planned risk
- $250.00
- Risk per share
- $2.00
- Actual risk
- $250.00
- Position value
- $12,500.00
- Buying power used
- 50%
How it works
Size the position from the risk—not the emotion
1. Define account risk
Choose the percentage of your account you are willing to risk on the trade.
2. Measure stop distance
The difference between entry and stop determines the dollar risk per share.
3. Calculate share quantity
Divide the planned dollar risk by the risk per share and round down.
Position size formula
Position size = account risk ÷ risk per share
Account risk equals account size multiplied by your chosen risk percentage. Risk per share equals the absolute difference between entry price and stop-loss price.
Example
- $25,000 account
- 1% risk per trade
- $100 entry
- $98 stop
- $250 planned risk
- $2 risk per share
- 125 shares
Important limitations
This calculator does not account for slippage, commissions, gaps, liquidity, leverage, or broker-specific buying-power rules.
It is an educational planning tool—not financial advice or a guarantee that losses will stay within the calculated amount.
Put the plan into practice
Record the risk plan with the trade.
Use TradeStaxx to connect your position size, notes, screenshots, execution, and post-trade lesson in one journal.