Kelly Criterion Calculator
Enter your bankroll, the decimal odds, and your true win probability to get the Kelly-optimal stake.
Kelly fraction
10.00%
Suggested stake
$100.00
Many bettors use half-Kelly to reduce variance.
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What Kelly does
The Kelly criterion sizes bets to maximise long-term bankroll growth: f = (b·p − q) / b, where b = odds−1, p = your win chance, q = 1−p. If the edge is negative, Kelly says do not bet.
Half-Kelly
Full Kelly is volatile. Many pros bet half-Kelly to cut swings while keeping most of the growth.