Expected Value (Betting) Calculator

Expected Value (EV) is the average amount of money you can expect to win or lose per bet if you placed the same wager under the same conditions an infinite number of times. A positive EV (+EV) means the bet is profitable over the long run, while a negative EV (-EV) means the sportsbook has the edge. Consistently placing +EV bets is the foundation of profitable sports betting.

The formula is: EV = (Win Probability × Profit If Win) − (Loss Probability × Wager). For example, if you bet $100 at +110 odds with a 52% win probability, your profit if you win is $110, and your loss if you lose is $100. EV = (0.52 × $110) − (0.48 × $100) = $57.20 − $48.00 = +$9.20. A positive result means the bet has value.

Use an EV calculator whenever you have your own probability estimate for a bet outcome — such as from a betting model, sharp sportsbook no-vig odds, or your own research. It helps you compare your estimated win probability against the implied probability in the odds, revealing whether the sportsbook is offering you value or pricing you out.

Implied probability is the win probability baked into the sportsbook's odds — it includes the vig (house margin). Your win probability is your independent estimate of how often you believe the bet will win, ideally based on sharp no-vig odds or a model. When your win probability exceeds the implied probability, you have a +EV bet.

For positive odds (underdog), enter the number as a positive value — for example, enter 110 for +110. For negative odds (favorite), enter a negative number — for example, enter -150 for -150. The calculator handles both formats and will compute your potential profit and EV correctly in both cases.

A positive EV means that, on average, you profit from this bet over many repetitions — the bet is worth taking if your probability estimate is accurate. A negative EV means you'd lose money on average. Most bets at standard sportsbooks are slightly negative EV due to the vig, so finding +EV opportunities requires sharp line shopping or your own accurate models.

Expected Value is expressed in dollar terms — the average profit per bet. Expected ROI (Return on Investment) expresses the same result as a percentage of your wager. For example, an EV of +$9.20 on a $100 bet equals an Expected ROI of +9.20%. ROI is useful for comparing the relative value of bets with different stake sizes.

The most common method among sharp bettors is using no-vig 'fair' odds from the sharpest sportsbooks in the world (like Pinnacle) and converting those to implied probabilities after removing the vig. You can also use your own statistical model, power ratings, or a consensus from multiple sharp books. The more accurate your probability estimate, the more reliable your EV calculation.