Implied Probability Calculator

Convert Betting Odds to Winning Chance

Enter the odds in any format (American, Decimal, or Fractional) to see the implied probability of the outcome.

Practical Examples

Click on an example to load its data into the calculator.

Favorite Team (American Odds)

american

Calculating the implied probability for a favorite team with negative American odds.

Odds: -150

Underdog Team (American Odds)

american

Calculating the implied probability for an underdog team with positive American odds.

Odds: 250

European Event (Decimal Odds)

decimal

Calculating the probability from common decimal odds used in Europe and Asia.

Odds: 1.75

UK Horse Racing (Fractional Odds)

fractional

Calculating the probability from fractional odds, popular in the UK.

Odds: 5/2

Other Titles
Understanding Implied Probability: A Comprehensive Guide
Learn how to convert betting odds into actionable probability insights to make more informed decisions.

What is Implied Probability?

  • From Odds to Percentages
  • The Market's Expectation
  • Not the True Probability
Implied probability is the likelihood of a particular outcome occurring as suggested by betting odds. It converts the odds set by bookmakers into a percentage, giving you a clearer picture of the market's expectation. It's not the 'true' probability, but rather the probability implied by the offered price, which includes the bookmaker's margin (vig).
Why is it important?
Understanding implied probability is the first step toward advanced sports betting. It allows you to assess whether a bet offers 'value'. If your own assessment of an event's probability is higher than the probability implied by the odds, you have found a value bet.

Step-by-Step Guide to Using the Implied Probability Calculator

  • Selecting the Odds Format
  • Entering the Odds
  • Interpreting the Result
1. Choose Your Odds Format
Start by selecting the type of odds you have from the dropdown menu: American, Decimal, or Fractional.
2. Input the Odds Value
Depending on your choice, the appropriate input fields will appear. For American odds, enter a positive or negative number. For Decimal, enter a number greater than 1. For Fractional, fill in both the numerator and denominator.
3. Calculate and Analyze
Click the 'Calculate Probability' button. The result will show the implied probability as a percentage. This percentage represents the chance of the outcome happening according to the bookmaker's odds.

Mathematical Formulas and Examples

  • American Odds Formula
  • Decimal Odds Formula
  • Fractional Odds Formula
American Odds Calculation
For positive (+) odds: Implied Probability = 100 / (Odds + 100). For negative (-) odds: Implied Probability = |Odds| / (|Odds| + 100). The absolute value of the odds is used for negative odds.
Decimal Odds Calculation
This is the simplest calculation: Implied Probability = 1 / Decimal Odds.
Fractional Odds Calculation
The formula is: Implied Probability = Denominator / (Numerator + Denominator).

Calculation Examples

  • American Odds (-110): 110 / (110 + 100) = 52.38%
  • Decimal Odds (2.50): 1 / 2.50 = 40.00%
  • Fractional Odds (2/1): 1 / (2 + 1) = 33.33%

Real-World Applications of Implied Probability

  • Sports Betting Strategy
  • Financial Market Analysis
  • Identifying Value
Finding Value Bets
The primary application for bettors is to identify value. If you believe a team has a 50% chance of winning, but the odds imply a 40% chance, that's a value bet. Your perceived probability is greater than the one offered by the bookmaker.
Understanding Bookmaker Margins
If you calculate the implied probabilities for all outcomes of an event, you'll find they add up to more than 100%. This extra percentage is the bookmaker's margin, also known as the 'vig' or 'juice'. It's how they guarantee a profit.

Common Misconceptions and Correct Methods

  • Implied vs. True Probability
  • Ignoring the Vig
  • Bankroll Management
Implied Probability is NOT True Probability
A common mistake is to assume implied probability is the actual, real-world probability of an outcome. It's crucial to remember that it's a reflection of the market, including the bookmaker's profit margin and public betting patterns. Always use your own analysis to estimate the true probability and compare it against the implied one.
The Importance of the 'Vig'
Ignoring the bookmaker's margin can lead to poor betting decisions. A bet might look good on the surface, but after accounting for the vig, it may not be profitable in the long run. Advanced bettors always factor in the vig when assessing odds.