Kelly criterion stake calculator
Optimal stake sizing for value bets. Kelly maximises long-run bankroll growth. Most pros bet 25-50% of full Kelly to absorb variance.
Recommended stake
€41.82
4.18% of your bankroll
Full Kelly fraction8.36%
Adjusted Kelly (×0.5)4.18%
How it works
Kelly fraction = (p × b − q) / b where b = odds − 1, q = 1 − p. Multiply by bankroll for stake.
Step by step
- Set bankroll, The total amount you bet with.
- Enter odds and probability, Decimal odds; true probability from your fair line.
- Pick Kelly fraction, Half-Kelly is a sane default.
FAQ
Why not full Kelly?
Variance. Full Kelly maximises long-run growth but the drawdowns are brutal, 50% pullbacks are common. Half-Kelly halves growth but cuts variance dramatically.
What if Kelly says zero or negative?
No edge, do not bet.