Kelly Criterion Calculator
The Kelly Criterion tells you the mathematically optimal fraction of your bankroll to stake on a bet, given your edge. Bet too much and variance can ruin you; bet too little and you leave growth on the table. This free Kelly calculator finds the sweet spot.
Enter the odds you're getting, your estimated win probability and your bankroll. It returns the full-Kelly stake, plus half- and quarter-Kelly — the fractional versions most serious bettors use to reduce swings.
Edge (EV)
9.20%
Stake (% of bankroll)
8.36%
Recommended stake
83.64
Serious about your edge?
ProfitBetting tracks every bet's closing line value against Pinnacle automatically — so you know if you're really beating the market, not just guessing.
Frequently asked questions
What is the Kelly Criterion formula?
For decimal odds o and win probability p, the Kelly fraction is (o·p − 1) / (o − 1). Multiply by your bankroll to get the stake. If the result is zero or negative, you have no edge and shouldn't bet.
Why use half or quarter Kelly?
Full Kelly maximises long-run growth but is very volatile, and it's unforgiving if your probability estimate is off. Half or quarter Kelly keeps most of the growth with far smaller drawdowns, so most bettors stake a fraction.
Where do I get the win probability?
From your own model, or by devigging a sharp book's odds to get a fair probability. Kelly is only as good as that estimate — garbage in, garbage out.
Related reading
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<p style="font:13px/1.4 system-ui,sans-serif;margin:8px 0 0">Free <a href="https://profitbetting.io/tools/kelly-calculator">Kelly Criterion Calculator</a> by ProfitBetting</p>