Kelly criterion calculator
The Kelly criterion is the bankroll fraction that maximises long-run growth. Plug in your odds, your edge, and your bankroll. The calculator returns the full Kelly stake plus half Kelly and quarter Kelly for the variance-averse.
Kelly in plain math
f* = (bp − q) / b, where b is the decimal odds minus one, p is your true win probability, and q = 1 − p. The result is the fraction of bankroll to bet. Full Kelly is mathematically optimal for log growth but extremely volatile in practice. Most professional bettors size at half or quarter Kelly to soften the swings.
If Kelly comes back negative, the bet is −EV and you shouldn’t take it.
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Every NotaSportsGuru pick is published with a stake that reflects the model’s edge and confidence. The Kelly math, applied in production since 2023. Members get the full slate.