Calculate a recommended bet size using the Kelly Criterion. Enter the odds and your estimated win probability to determine what fraction of your bankroll to wager. Results vary and are never guaranteed — only use disposable income.
Calculate a recommended bet size using the Kelly Criterion. Enter the odds and your estimated win probability to determine what fraction of your bankroll to wager. Results vary and are never guaranteed — only use disposable income.
Expected Value
153.64%
Fraction of Bankroll to Wager
5.91%
Amount to Wager with $10000 bankroll
$591
Kelly Criterion calculates the optimal fraction of your bankroll to wager to maximize long-term growth. The multiplier (typically 0.25) reduces the Kelly fraction to minimize risk while still capturing most of the growth benefit.
The Kelly Criterion is a mathematical formula developed by John L. Kelly Jr. at Bell Labs in 1956. It calculates a fraction of your bankroll to wager on a bet with positive expected value, attempting to balance bankroll growth against the risk of large drawdowns. Results vary and are never guaranteed.
The formula is: f = (bp - q) / b, where f is the fraction of bankroll to wager, b is the decimal odds minus 1 (net profit per dollar bet), p is the probability of winning, and q is the probability of losing (1 - p).
Full Kelly sizing can lead to high variance. Many experienced bettors use a fractional Kelly approach (such as 0.25x or "quarter Kelly") to reduce variance. This calculator lets you adjust the multiplier to match your risk tolerance. Combine this with our Expected Value Calculator to first confirm a bet is +EV before sizing it.