Kelly Criterion Calculator
Optimal bet size from win rate and payoff.
Your numbers
Full Kelly
25.0%
Half Kelly (safer)
12.5%
The link and the printed sheet both save your numbers, so anyone who opens them sees the same estimate.
Compare scenarios
Save your current numbers, change them, save again, and see each estimate side by side. Saved in this browser only.
How it works
Kelly % = W − (1 − W) ÷ R.
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Results are estimates for education only and are not investment advice.