What the expected value is

The expected value of a bet is the average amount a player can expect to win or lose for a specific bet. It can be understood as the quantity of money per bet the player would lose or win if the exact same bet, with the same probabilities, were played an infinite number of times. It is calculated with this formula:

e: expected value
w: actual probability of winning
p: potential prize (the reward as percentage of the initial bet)
l: actual probability of losing

e = wp - l

This number, e, is the percentage of the money gambled that can be expected to be earned or lost per bet.

Calculator and simulator

This calculator gives you the expected value for any combination of decimal odds and actual probabilities. It also simulates bets with those chances thousands of times, to demonstrate to you how in the long term the average money earned or lost per bet gravitates towards the expected value.

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