top of page

EV Calculator

Expected value (EV) in sports betting is the average profit or loss you can expect over the long run based on your estimated win probability and the sportsbook’s odds. A positive EV bet is profitable over time.

How to Calculate EV

Expected value, or EV, measures the average profit or loss you can expect from a bet over the long run. To calculate EV, you compare your estimated true probability of winning to the payout offered by the sportsbook.

EV Formula as a Dollar Amount

EV = (Win Probability × Profit if You Win) − (Loss Probability × Amount Risked)

​

Where:

  • Win Probability = your estimated chance the bet wins

  • Loss Probability = 1 − Win Probability

  • Profit if You Win = net profit, not total payout

  • Amount Risked = your stake

​

Example​

Step 1: Calculate potential profit

At +120 odds, a $100 bet returns $120 in profit if it wins.

 

Step 2: Calculate loss probability

If your win probability is 50%, then your loss probability is also 50%.

 

Step 3: Plug the numbers into the formula

EV = (0.50 * 120) - (0.50 * 100)
EV = 60 - 50
EV = $10

​

That means for every $100 wagered, your expected value is +$10.

EV Formula as a Percentage

You can also express EV as a percentage:

​

EV (%) = (Win Probability × Decimal Odds) − 1

​

This version shows your expected return per dollar wagered.

​

If the result is:

  • Greater than 0: the bet is positive EV (+EV)

  • Less than 0: the bet is negative EV (-EV)

​

Example​

American odds of +120 convert to decimal odds of 2.20. So:

 

EV (%) = (0.50 × 2.20) − 1
EV (%) = 1.10 − 1
EV (%) = 0.10 = 10%

 

This bet has a +10% edge.​

What This Means

This doesn't mean you'll win $10 on this specific bet. It means that if you could place this same bet many times at the same odds with the same win probability, you'd expect to earn an average profit of $10 per $100 wagered over time.

EV Calculator FAQ

What is EV?

  • Expected value (EV) is the average profit or loss you can expect per bet in the long run. If EV is positive, the bet is profitable in the long run. If EV is negative, the bet is losing in the long run.

​​

What does the EV Calculator do?

  • The EV Calculator helps you calculate expected value in sports betting by comparing your projected win probability to the odds offered by the sportsbook. To use the calculator, enter your estimated win probability and the American odds of the bet, and the calculator will show you the EV of the bet.

​​

How do you calculate EV in sports betting?

  • You calculate EV by multiplying your probability of winning by your profit if the bet wins, then subtracting your probability of losing multiplied by your stake. In percentage terms, the formula is:

    • Edge (%) = (Win Probability * Decimal Odds) − 1

    • If the result is above 0, the bet is +EV and expected to win money over the long run. If the result is below 0, the bet is -EV and expected to lose money over the long run.

​​

What is a +EV bet?

  • A +EV bet is a wager where the sportsbook’s odds are better than the true odds of the outcome ("true" meaning based on your projection). For example, if you think a team wins 55% of the time but the odds are +100 (implying only 50% win probability), then the bet has positive expected value. Sharp sports bettors only bet with +EV.

​​

What’s the difference between EV and edge?

  • Some bettors use “EV” for dollar expectation and “edge” for percentage expectation, but they're typically used interchangeably. They mean same thing if they're both expressed as a percentage, and both refer to expected long-term return relative to the price.

​​

How do you estimate true probability for EV?

  • You estimate true probability by creating your own projection of how often a bet should win. That projection can come from your model, handicapping process, or no vig fair odds from a sharp market. The usefulness of your EV calculation depends on how accurate your probability estimate is.

​​

Why is EV important in sports betting?

  • EV is among the most important concepts in sports betting. Understanding EV shifts your perspective from "picking winners" to finding good prices. This is the main difference between sharp and square/recreational bettors. A sharp bettor knows a bet can lose today and still be a good bet if it was +EV.

​​​

Learn More About Betting Calculators

Check Out These Articles on a Range of Sports Betting Math Topics

bottom of page