Enter your estimated win probability and the decimal odds available. The calculator shows expected value (EV%) and the mathematically optimal Kelly stake.
Your honest estimate, not the bookmaker’s implied %
For stake amount in £/$/€
Expected Value
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Kelly Stake
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Half-Kelly (recommended)
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Kelly criterion maximises long-run bankroll growth but assumes accurate probability estimates. Half-Kelly reduces variance. For entertainment purposes only. 18+ | gambleaware.org