Kelly Criterion Calculator
Find the mathematically optimal stake for a bet given your edge, using the Kelly criterion.
How to use the kelly criterion calculator
- Enter the decimal odds and your estimated win probability.
- Optionally enter your bankroll for a stake amount.
- Click Calculate for the Kelly fraction and amount.
Only as good as your estimate
Kelly assumes you know your true win probability. Overestimate your edge and Kelly will tell you to over-bet, so conservative fractions are safer in practice.
Frequently asked questions
What is the Kelly criterion?
A formula for the stake size that maximises long-term bankroll growth. It bets more when your edge is larger and nothing when you have no edge.
Should I bet full Kelly?
Most experienced bettors use half or quarter Kelly. Full Kelly maximises growth but produces large swings, and it is very sensitive to errors in your probability estimate.
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