Kelly Criterion Calculator
Use the Kelly Criterion formula to determine the mathematically optimal percentage of your bankroll to risk on each trade.
%
Your historical win percentage
Average win size divided by average loss size
$
Results
Kelly %25.00%
Half Kelly %12.50%
Quarter Kelly %6.25%
Full Kelly Amount$2500.00
Half Kelly Amount$1250.00
FAQ
What is the Kelly Criterion?›
The Kelly Criterion is a mathematical formula that determines the optimal percentage of capital to risk on a bet or trade. It maximizes long-term growth rate by balancing potential gains against potential losses based on your win rate and payoff ratio.
Should I use the full Kelly or a fraction?›
Most traders use a fraction of the Kelly percentage (commonly half-Kelly or quarter-Kelly) because full Kelly can produce large swings. Fractional Kelly reduces volatility significantly while giving up only a small amount of long-term growth.