The Kelly criterion turns an edge into a stake size. Enter your win probability and the odds, then choose full, half or quarter Kelly.
No. 1 Our pick
Prime Sports Funded Stake range set, clock off
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1 Game time
Your edge, your stake
Enter the probability you assign to the bet, not the one the price implies. Odds can be American (-110) or decimal (1.91). The bankroll is optional.
Other calculators: risk of ruin, hedge, parlay and odds.
2 The stat sheet
The formula behind the stake
Share of the bankroll Stake = (b × p − q) ÷ b
Here b is the decimal odds minus 1, p your win probability and q = 1 − p. At 55% and -110 (1.91), the edge is 5% of each dollar staked and the full Kelly stake is 5.5% of the bankroll.
Kelly assumes p is right. The Kelly criterion guide shows what an overestimate of two points does to the drawdowns.
No edge, no stake: below the break-even rate, Kelly gives zero.
The turning point
Kelly inside a stake range
In a challenge, the operator sets the stake range. At Prime Sports Funded, a stake runs from 2% to 5% of the starting balance: a 5.5% Kelly stake is capped at 5%, and half Kelly fits inside the range.
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Frequently asked questions
What Kelly fraction should you use?
Most bettors use half or quarter Kelly. Your probability is an estimate, and overestimating it by two points nearly doubles the full Kelly stake. A fraction keeps most of the growth with much smaller drawdowns.
What if the Kelly stake is zero?
Then your probability does not beat the price: there is no edge at these odds, and Kelly says pass.
Can you use Kelly on a parlay?
Yes, with the parlay's combined odds and your probability that every leg wins. Errors in each leg compound, so a small fraction is safer.
The verdict
Size the stake, skip the clock
One step at +35%, no time limit.
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