Work out kelly criterion stake instantly with clear inputs, formula shown and shareable results.
The Kelly fraction is (p x b - (1 - p)) / b, where b is decimal odds minus one; a zero or negative result means the bet has no edge and should not be backed. Full Kelly maximises long-run growth but with brutal variance, which is why most professionals stake a half or quarter of the Kelly figure.
Kelly fraction
f = (p x b - (1 - p)) / b, with b = decimal odds - 1
Edge
edge = p x decimal odds - 1
f = (p x b - (1 - p)) / b, with b = decimal odds - 1. The Kelly fraction is (p x b - (1 - p)) / b, where b is decimal odds minus one; a zero or negative result means the bet has no edge and should not be backed.
Full Kelly maximises long-run growth but with brutal variance, which is why most professionals stake a half or quarter of the Kelly figure.
Enter bankroll, decimal odds, your estimated chance of winning. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.