Expected Value Betting Calculator
+EV check from odds and true probability.
How to Use This Calculator
- Select your odds format (Decimal, Fractional, or American)
- Input the bookmaker’s odds for the selection
- Input your estimated true win probability (as a percentage)
- Input your intended stake amount
- Read off the expected value, edge percentage, and the +EV verdict
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
Define expected value in betting.
Expected value (EV) is the average amount you expect to win or lose per bet across the long run. Positive EV (+EV) marks a bet that profits long-term, while negative EV (-EV) means losses accrue over time.
What does +EV signify?
A +EV (positive expected value) bet means you hold an edge over the bookmaker. Place +EV bets consistently and you turn a profit long-term, even though individual bets can still lose.
How is true probability estimated?
Estimate true probability via your own research, statistical models, or by comparing odds across multiple bookmakers. The objective is a more accurate probability read than the bookmaker holds.
Can a +EV bet still lose money?
Yes, individual +EV bets can lose. Expected value is a long-term concept. Across hundreds or thousands of bets positive EV yields profit, but short-term variance makes individual losses routine.