Expected Value Sports Calculator
Check if a bet is +EV from odds and the true chance.
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)
- Add the stake amount you’re planning to bet
- See 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 when betting?
Expected value (EV) is the average you can expect to win or lose per bet over the long run. Positive EV (+EV) means the bet pays off over time, while negative EV (-EV) means you’ll lose money in the long run.
What does +EV actually mean?
A +EV (positive expected value) bet means you’ve got an edge on the bookmaker. Keep placing +EV bets and you’ll come out ahead over the long run, even though any single bet can still lose.
How do I work out the true probability?
You can estimate true probability from your own research, statistical models, or by comparing odds across several bookmakers. The trick is having a sharper probability estimate than the bookmaker does.
Can a +EV bet still lose me money?
Yes, any single +EV bet can lose. Expected value is a long-term idea. Across hundreds or thousands of bets, positive EV turns into profit, but short-term swings mean the odd loss is totally normal.