Position Size Calculator
Calculate the correct number of shares or contracts to trade based on your account size and risk tolerance.
CFA, CMT — Chartered Financial Analyst & Chartered Market Technician
Former institutional trader with 15 years experience across equities, forex and derivatives. Now focused on financial education.
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About the Position Size Calculator
Position sizing determines how many shares to buy so a losing trade never exceeds your pre-defined risk per trade. Risk no more than 1–2% of your account on any single trade.
Formula: Shares = (Account × Risk%) ÷ |Entry − Stop|
Tips to improve your result
- 1.
Reduce risk to 0.5% when testing a new strategy.
- 2.
Never increase position size to "make back" a loss — this is how accounts blow up.