Intimidated by the formula shown in the featured image? Worry not!
Tada~

Kelly Criterion Calculator

*Input area: Win Probability is your estimated chance of winning. If it's a coin toss, put 50.
Reward Ratio is the expected reward you get per risk. Let's say if you win the coin toss the payout is 1.5 for betting 1, put 1.5. (Please note that the payout excludes your bet. Eg. in a casino if you bet $1 and the payout is $2.5, you only win $1.5 because $1 is yours to begin with)

Output = Bet size with the highest value mathematically. If it shows 20% and you have $10,000 in your capital, risking $2000 gives you the highest expected return.