Betting Calculators
Expected Value Calculator
Determine if a bet has positive expected value (+EV). Enter odds and your estimated true probability to see if the bet is profitable long-term.
How to Use This Calculator
- Select 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 your planned stake amount
- View the expected value, 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 amount you expect to win or lose per bet over the long run. A positive EV (+EV) means the bet is profitable long-term, while negative EV (-EV) means you will lose money over time.
What does +EV mean?
A +EV (positive expected value) bet means you have an edge over the bookmaker. If you consistently place +EV bets, you will be profitable in the long run, even though individual bets can still lose.
How do I estimate the true probability?
You can estimate true probability using your own research, statistical models, or by comparing odds across multiple bookmakers. The key is having a more accurate probability estimate than the bookmaker.
Can I lose money on +EV bets?
Yes, individual +EV bets can lose. Expected value is a long-term concept. Over hundreds or thousands of bets, positive EV will result in profit, but short-term variance means individual losses are normal.