Expected Value Betting Tool
Determine whether a wager is +EV from the odds and your estimated true probability.
How to Use This Calculator
- Choose the odds format you prefer (Decimal, Fractional, or American)
- Enter the bookmaker’s odds for the selection in question
- Enter your own estimate of the true winning probability, expressed as a percentage
- Enter the stake you intend to place
- The tool then reports the expected value, the edge percentage, and whether the bet qualifies as +EV
Formula
Expected Value = (Win Probability × Profit) - (Loss Probability × Stake)
EV per unit = (p × (Decimal Odds - 1)) - (1 - p)
Edge % = EV per unit × 100
Where p = your estimated win probability (as a decimal)
Frequently Asked Questions
What is expected value in betting?
Expected value (EV) is the average sum you can anticipate winning or losing on each bet across the long run. A positive EV (+EV) marks a bet as profitable over time, whereas a negative EV (-EV) means you stand to lose money as the bets accumulate.
What is the meaning of +EV?
A +EV, or positive expected value, bet signals that you hold an edge over the bookmaker. Place +EV bets consistently and you will profit in the long run, even though any single bet remains capable of losing.
How can I estimate the true probability?
You might gauge true probability through your own research, statistical models, or a comparison of odds across several bookmakers. What counts is arriving at a probability estimate sharper than the bookmaker’s.
Is it possible to lose on +EV bets?
Yes; any single +EV bet can lose. Expected value is a long-term notion. Over hundreds or thousands of bets, positive EV translates into profit, but short-term variance makes individual losses entirely ordinary.