Kelly Criterion Calculator
Find your optimal bet size using the Kelly formula. Maximize long-term growth while managing risk with mathematical precision.
Your estimated probability of winning this bet (0-100%)
The odds offered by the sportsbook (e.g., -110, +150)
Lower values reduce bet size for safer bankroll management
The Kelly Criterion is a mathematical formula used to determine the optimal size of a series of bets to maximize long-term growth while minimizing risk of ruin.
Key Benefits:
- Maximizes long-term growth rate
- Prevents betting too much (risk of ruin)
- Prevents betting too little (missed opportunities)
- Based on mathematical proof
Important Notes:
- Requires accurate probability estimates
- Can recommend large bet sizes
- Consider using fractional Kelly (25-50%)
- Only bet when you have an edge (positive EV)
Remember: The Kelly Criterion assumes you have an accurate estimate of your win probability. If you're wrong, you could lose more than optimal.
What is the Kelly Criterion?
The Kelly Criterion is a mathematical formula used to determine the optimal bet size for maximizing long-term growth of your bankroll. It balances potential returns against the risk of ruin.
How do I calculate my win probability?
Win probability should be your honest assessment of how likely you are to win the bet. This could be based on your research, models, or analysis. It should be more accurate than the implied probability from the odds.
What is risk tolerance in Kelly betting?
Risk tolerance allows you to reduce your bet size below the full Kelly recommendation. Many professional bettors use 25-50% of Kelly to reduce volatility while still maintaining positive expected growth.
When should I avoid a bet according to Kelly?
If the Kelly percentage is negative, it means the bet has negative expected value and you should avoid it entirely. The bet is not profitable in the long run.