- Enter your bankroll in pounds, euro or any other currency. Bankroll is basically the amount of money you plan to use for betting - do not gamble more than you can afford to lose!
- Commission is what you pay to your betting exchange. If you bet at traditional bookmakers, commission is 0, but you will probably get slightly better odds at betting exchanges.
- This calculator uses decimal odds, so you can't use fractional odds used in the UK or American odds. If you need to convert fractional odds to decimal, you can use our handy odds converter.
- Your estimated probability of the event you are backing is crucial for Kelly criterion to work. If you're not sure you can estimate your team's chances correctly, Kelly calculator won't help you.
- There are basically three different modes you can use in this calculator - use 1/2 Kelly or 1/4 Kelly for more cautious approach.
- Odds with deducted commission is actually odds you get after betting exchanges get their commission.
- Fair odds are the odds based on your estimated probability.
- Value in this calculator will tell you if you have potential value bet. It should be higher than one (1.00) if you plan to back your selection. If this value is lower than 1, you should consider laying the selection.
- This calculator will give you the optimal stake based on odds, bankroll and percentages you entered. If you get negative number, your bet is a lay candidate.
- This value is based on the bankroll value you entered! Do not bet more than you can afford! If you get negative number, your bet is a lay candidate. If you get value greater than 10%, you probably did your maths wrong!
The Kelly criterion or Kelly strategy or Kelly Staking Plan is a formula used to determine the optimal size of a series of bets.
Kelly Criteria was developed in 1956 by John L. Kelly and was designed to maximize the growth of your bank roll over the long term.
Main problem with The Kelly Criteria is estimations of percentages for certain event which are should be better than the bookmakers’ estimations.
Formula for determining optimal size of stakes is:
Stake = ((Odds *Perc) - 1) / (Odds - 1) * 100
- Odds = Odds offered for certain event by bookmaker
- Stake = Optimal size of stake
- Perc = Estimation of percentages for certain event
For example, your bank roll is £1000, and you decide to bet on football team who is priced @2.20 by your bookmaker. You also estimated chances of your team to win the match and probability for your team to win is 50%. According to Kelly formula, optimal size of your stake would be: Stake = ((2.20*0.50)-1)/(2.20-1)*100 = 0.833 = 8.33%
So, the optimal size of your stake in this example would be 8.33% of your bank roll, or 8.33% * £1000 = £83.
The Kelly Criteria is popular with many professional punters, but as mentioned above, the main problem is to precisely estimate percentages in certain betting event. If you think you are able to estimate percentages of a football match better than your bookmaker, than Kelly Staking is right staking plan for you, and this calculator will help you determine your optimal stakes.