Expected Value Calc
Is it +EV? Check from odds and your true-chance estimate.
How to Use This Calculator
- Pick your odds format (Decimal, Fractional, or American)
- Enter the bookmaker’s odds for the selection
- Enter your estimated true probability of winning, as a percentage
- Enter the stake you plan to put down
- See the expected value, the edge percentage, and whether the bet is +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 you can expect to win or lose per bet over the long haul. Positive EV (+EV) means the bet pays off long-term; negative EV (-EV) means it bleeds money over time.
What does +EV actually mean?
A +EV (positive expected value) bet means the edge is on your side, not the bookmaker’s. Stack up +EV bets consistently and you’ll profit in the long run — even though plenty of individual bets will still lose.
How do I estimate the true probability?
Build it from your own research, statistical models, or by comparing odds across several bookmakers. The whole game is landing on a sharper probability estimate than the bookmaker has.
Can a +EV bet still lose money?
Absolutely — single +EV bets lose all the time. Expected value is a long-game concept. Across hundreds or thousands of bets, positive EV turns into profit, but short-term variance means individual losses are just part of the deal.