Kelly Criterion Calculator
Calculate the mathematically optimal position size to maximise long-run growth without risking ruin.
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.
Related calculators
Position Size Calculator
Calculate the correct number of shares or contracts to trade based on your account size and risk tolerance.
Win Rate & Expectancy Calculator
Calculate your trading system's statistical edge: expectancy and profit factor.
Risk/Reward Ratio Calculator
Calculate the risk-to-reward ratio of a trade and see the dollar amounts at stake.
About the Kelly Criterion Calculator
The Kelly Criterion maximises long-run growth. In practice, use Quarter Kelly (25%) to reduce variance and emotional pressure.
Formula: Kelly % = W − (1−W)/b where W = win rate, b = avg_win/avg_loss