Kelly Criterion Betting Calculator
Calculate optimal bet size using Kelly Criterion formula for maximum long-term growth
About this calculator
The Kelly Criterion Betting Calculator determines the optimal percentage of your bankroll to wager on a bet to maximize long-term growth while minimizing risk of ruin. This mathematical formula, developed by John Kelly Jr., considers both the probability of winning and the odds offered to calculate the ideal bet size. It's essential for serious bettors and investors who want to optimize their betting strategy and achieve sustainable profit growth over time.
How to use
Enter your estimated probability of winning the bet as a percentage, input the decimal odds offered by the bookmaker, and specify your current bankroll amount. The calculator will instantly display the recommended bet amount and percentage of your bankroll to wager according to the Kelly Criterion formula.
Frequently asked questions
What happens if the Kelly percentage is negative?
A negative Kelly percentage means the bet has negative expected value and you shouldn't place it. The formula indicates this wager would lose money over time.
Should I always bet the full Kelly amount?
Many experts recommend betting a fraction (25-50%) of the Kelly amount to reduce volatility while still achieving good long-term growth with lower risk.
How accurate do my win probability estimates need to be?
Accuracy is crucial since the Kelly formula is sensitive to probability estimates. Overestimating win probability can lead to overbetting and significant losses.