Free Kelly Criterion Bet Size Calculator Online
Calculate the mathematically optimal capital allocation percentage to maximize geometric wealth growth while avoiding ruin. — 100% free online utility, zero sign-up, zero paywalls, and private client-side processing.
How It Works
Enter Win Rate Probability
Input historical strategy win rate percentage (e.g., 55%).
Enter Win/Loss Ratio
Input average win dollar amount divided by average loss dollar amount (e.g., 1.8).
Calculate Full Kelly %
View the theoretical growth-maximizing portfolio fraction.
Apply Fractional Kelly
Use Half-Kelly (0.5x) or Quarter-Kelly (0.25x) to eliminate severe portfolio volatility.
Frequently Asked Questions
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