Expected value calculator
Check whether a price is worth it at your own probability.Change any field and the result updates.
Inputs are kept in the URL so you can share the result.
How it works
Expected value is what a bet returns on average if you could place it many times: your probability of winning times the profit, less your probability of losing times the stake.
Worked example. At 2.50 a stake of 10.00 makes a profit of 15.00 when it wins. With your probability of 45%: 0.45 × 15.00 − 0.55 × 10.00 = 6.75 − 5.50 = +1.25, which is +12.5% of the stake.
A positive value means the price pays more than your probability needs; a negative value means it pays less. The result is only as good as your probability.
FAQ
Where does my probability come from?
From you: it is your own estimate of the chance. The implied probability of the price, which the odds converter shows, is the bookmaker's view with its margin.
Does a positive expected value mean I will win?
No. It is an average over many bets like this one; any single bet can lose.