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.
Want the stakes the model already sized?
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.