Calculate the expected value of any sports bet to find your mathematical edge over the sportsbook. The only bets worth placing long-term are +EV bets — this tool shows you which ones qualify.
Expected value (EV) is the average profit or loss you would earn per bet if you placed that exact bet an infinite number of times. A +EV bet earns money on average; a -EV bet loses it. Most bets at retail sportsbooks are -EV because the book's vig means the implied probability always sums to more than 100%. Sharp bettors ignore the outcome of any individual bet and focus entirely on whether the bet's price was +EV before it was placed.
EV = (Probability of Winning × Profit if Win) − (Probability of Losing × Loss if Lose). For a $100 bet at +200 odds that you estimate has a 40% true win probability: EV = (0.40 × $200) − (0.60 × $100) = $80 − $60 = +$20. That bet has an expected value of +$20, meaning for every $100 staked you expect to average $20 in profit over a large sample.
The hardest part of EV calculation is estimating the true probability. The most objective method is to use no-vig odds derived from the sharpest available market. Strip the vig from pinnacle or a consensus line, and the resulting implied probability is the market's best estimate of the true odds. If a retail book is pricing a team at a higher implied probability than the no-vig line, the other side is +EV by definition. PromoGrind's no-vig calculator feeds directly into the EV tool to streamline this process.
Sports betting is a negative-sum game at the retail level — the vig ensures that if you bet enough random wagers, you will lose. The only escape is consistent +EV. Handicapping skill, line shopping, and promo extraction are all methods of generating edge. Without demonstrated positive EV, no staking system or bankroll approach can produce long-term profit.