Expected Value Calculator
Expected value (EV) tells you the average profit or loss per bet at a given price if you place the same wager many times. Positive EV means the bet is profitable in the long run, given that your probability estimate is correct.
Result
EV formula
EV = (P_win × profit_if_win) − (P_lose × stake)
Profit if win = stake × (decimal_odds − 1). Loss if lose = stake. P_lose = 1 − P_win.
Example
You think a side has 55% chance to win at +100 (decimal 2.00). EV = (0.55 × $100) − (0.45 × $100) = $55 − $45 = $10. You expect $10 profit per $100 wager, on average, in the long run.
How to use this
EV is only meaningful if your probability estimate is well-calibrated. Compare your number to the no-vig fair odds (use the no-vig calculator) and to consensus among sharp books. If your estimate is consistently inflated, your EV calculations will mislead you into bad bets.
Frequently Asked Questions
What is expected value in sports betting?
Expected value (EV) is the average profit or loss per bet at a given price if you placed the same wager many times. Positive EV means the bet is profitable in the long run, assuming your probability estimate is correct. Most sports bets at retail books have negative EV due to vig.
How do I find positive EV bets in Tennessee?
Estimate your win probability for a market. Compare against the book's implied probability (use the implied probability calculator). If your number is higher than the book's, the bet has positive EV. Line shopping across multiple TN books increases the chance of finding mispriced markets.
How accurate does my probability estimate need to be?
Critically accurate. EV math is only meaningful if your probability estimate is well-calibrated. Track your results over hundreds of bets and compare your predicted hit rate against actual. If consistently inflated, your EV calculations are misleading you into bad bets.
What's a realistic positive EV in sports betting?
Sharp sports bettors typically operate on 2 to 5% EV per bet. Beginners who think they have 20% EV usually have closer to -5% (negative EV with overestimation). Be conservative when estimating edge.
Does EV account for bonus bets and promos?
No, this calculator computes raw EV on a single cash bet. Bonus bets, parlay insurance, and odds boosts can flip a slightly negative-EV bet into positive EV. Use the bonus bet calculator separately to compute promo-adjusted value.