Kelly Criterion Calculator

Optimal stake size from your edge

Kelly criterion calculator: from your estimated probability and the odds, get the mathematically optimal fraction of bankroll to stake.

Bankroll Odds (decimal) Your estimated probability % Kelly fraction

FAQ

What is the Kelly criterion?

A formula for bet sizing that maximizes long-term bankroll growth: f = (bp − q) / b.

Why use half Kelly?

Full Kelly is volatile; half Kelly keeps ~75% of the growth with far less variance.

We do not promote or encourage betting — this tool is for educational and analytical purposes only. 18+, play responsibly.

Want ready predictions built on this math?

Our engine analyzes every match automatically: 1X2, goals, predicted score and more.