Free Tool
Kelly Criterion Calculator
Find the mathematically optimal amount to stake for long-term bankroll growth. Enter the odds, your estimated win probability, and your bankroll — then choose Full, Half, or Quarter Kelly to match your risk tolerance. Completely free, no account needed.
Kelly Criterion Calculator
Full Kelly suggests staking 8.33% of your bankroll. Most bettors use Half or Quarter Kelly to reduce volatility while keeping most of the long-term growth.
Informational tool only — not betting advice. The Kelly Criterion relies entirely on your own probability estimate; an overestimate leads to over-betting. 18+. Bet responsibly at licensed operators.
Enter the odds & probability
Type the odds and your own estimated chance the bet wins. Kelly only creates value when your estimate beats the odds' break-even line.
Add your bankroll
Enter your total bankroll so the calculator turns the optimal fraction into a concrete dollar stake.
Pick a Kelly fraction
Full Kelly maximizes growth but is volatile. Half or Quarter Kelly keeps most of the upside with far smaller swings.