What is the Kelly Criterion?
The Kelly Criterion is a staking formula that calculates the optimal fraction of your bankroll to wager when you believe you have an edge. It is designed to maximise long-term bankroll growth while protecting you from the risk of ruin.
Enter the odds, your honest estimate of the win probability, and your total bankroll. The calculator returns the full Kelly stake along with the more conservative half and quarter Kelly amounts.
Frequently asked questions
How does the Kelly Criterion work?
It divides your edge by the odds to find the ideal stake fraction. The bigger your edge over the odds, the larger the recommended bet relative to your bankroll.
What is fractional Kelly?
Many bettors stake only half or a quarter of the full Kelly amount. This sacrifices a little long-term growth in exchange for a much smoother, less volatile bankroll.
What if Kelly says to bet zero?
A zero or negative result means the odds do not offer value at your estimated win probability. In that case the formula recommends not placing the bet at all.