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Expected Value Calculator

Find out if your bet has positive or negative expected value

Calculate Expected Value

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How to Use This Calculator

1. Enter the odds in your preferred format (American or Decimal)

2. Enter your stake amount (how much you plan to bet)

3. Enter your estimated probability of this bet winning (0-100%)

4. Click Calculate to see if your bet has positive or negative expected value

The key to profitable betting is finding bets where your estimated probability is higher than what the odds imply.

Why Expected Value Matters

Expected Value (EV) is the average amount you can expect to win or lose on a bet if you were to place it multiple times. It combines the probability of winning with the potential payout.

Positive EV (+EV) means over the long run, you'll make money on this type of bet.

Negative EV (-EV) means over the long run, you'll lose money on this type of bet.

Professional bettors focus on finding +EV opportunities rather than trying to pick winners. This mathematical approach leads to long-term profitability.

How To Use This Expected Value Calculator

Follow these steps to calculate the expected value of your sports bets:

  1. Select Odds Format: Choose between American odds (e.g., +150, -110) or Decimal odds (e.g., 2.50, 1.91) based on your preferred format.

  2. Enter Odds: Input the odds offered by your sportsbook in your selected format.

  3. Input Stake Amount: Enter how much you plan to wager on this bet.

  4. Enter Your Probability: Input your estimated probability (in percentage) that the bet will win. This should be based on your research and analysis.

  5. Analyze Results: After clicking "Calculate," review whether your bet has positive or negative expected value, along with the specific dollar amount and percentage.

Pro Tip: Finding Your Edge

The key to successful sports betting is identifying situations where your estimated probability is higher than the sportsbook's implied probability. This difference is your "edge," and the larger the edge, the more valuable the betting opportunity.

Focus on sports or markets where you have specialized knowledge that might give you better insight than the general betting public.

Expected Value (EV) FAQs

What is Expected Value in sports betting?

Expected Value (EV) is a mathematical concept that represents the average amount you can expect to win or lose per bet if you were to place the same bet multiple times. It's calculated by multiplying potential outcomes by their probabilities and then summing these values.

How is Expected Value calculated?

For sports betting, the formula is:
EV = (Probability of Win × Potential Profit) - (Probability of Loss × Stake)

For example, if you bet $100 at +200 odds with a 40% chance of winning:

  • Potential profit: $200
  • Win probability: 0.4 (40%)
  • Loss probability: 0.6 (60%)
  • EV = (0.4 × $200) - (0.6 × $100) = $80 - $60 = $20
This means that, on average, you would expect to profit $20 for every $100 wagered on this bet over the long run.

Why is the implied probability important?

The implied probability is what the sportsbook odds suggest about the likelihood of an outcome. It represents the "fair price" threshold. If your estimated probability is higher than the implied probability, the bet has positive expected value. This comparison forms the foundation of value betting.

Should I always bet when I find positive expected value?

While positive EV bets should be profitable over the long run, you should also consider:

  • Your confidence in your probability estimate
  • Your bankroll management strategy
  • The size of your edge (larger edges warrant larger bets)
  • Your overall betting portfolio (avoid overexposure to correlated outcomes)
Many professional bettors use the Kelly Criterion to determine optimal bet sizing once they've identified +EV opportunities.

Why might my EV calculations be wrong?

Common reasons for inaccurate EV calculations:

  • Probability estimation errors: Your assessment of an outcome's likelihood might be inaccurate
  • Overlooking vig/juice: Sportsbooks build a margin into their odds
  • Ignoring correlations: Some bets are affected by the outcomes of others
  • Incomplete information: Key factors like injuries or weather may not be accounted for
Remember that EV calculations are only as good as the inputs you provide.

Expected Value Betting Strategy

Benefits of EV-Based Betting
  • Long-Term Profitability: Consistently betting with positive EV leads to profits over time, even if you lose individual bets.

  • Objective Decision-Making: Removes emotional bias from betting decisions by focusing on mathematical value rather than "feelings" about games.

  • Portfolio Approach: Allows you to compare the value of different betting opportunities and allocate your bankroll optimally.

  • Scalability: The approach works across different sports, markets, and bet types as long as you can accurately estimate probabilities.

Challenges of EV-Based Betting
  • Probability Estimation: Accurately estimating true probabilities of sporting events is difficult and requires significant expertise.

  • Sample Size Issues: Sports betting offers relatively few opportunities compared to casino games, making variance a significant factor.

  • Market Efficiency: Popular markets become increasingly efficient as sportsbooks and sharp bettors adjust their assessments.

  • Psychological Discipline: Maintaining discipline through inevitable losing streaks, even when betting with positive EV, can be challenging.


Building Your EV Betting System

Building an effective expected value betting system requires several components:

1. Probability Model: Develop a systematic approach to estimating outcome probabilities. This could range from statistical models to fundamental analysis of teams/players.

2. Odds Evaluation: Compare your probability estimates to market odds to identify value. Tools like this EV calculator streamline this process.

3. Bankroll Management: Implement a staking plan (like the Kelly Criterion) to determine appropriate bet sizes based on your edge and bankroll.

4. Record Keeping: Track all bets, including your pre-bet probability estimates, to evaluate and improve your system over time.

5. Continuous Learning: Regularly review your performance to identify strengths, weaknesses, and biases in your probability assessments.

While no betting system guarantees short-term results, a disciplined expected value approach gives you the best chance for long-term profitability in sports betting.

Related Resources

Learn More About EV

Deepen your understanding of expected value concepts and how to apply them to different betting markets.

EV Betting Guide
Kelly Criterion Calculator

Once you've identified +EV bets, use the Kelly Criterion to determine the optimal bet size for your bankroll.

Kelly Calculator
Calculate Vig

Calculate the bookmaker's margin to understand how much edge you need to overcome for a profitable bet.

Vig Calculator