OddsEdgeMargin calculator
Enter the odds for every outcome to see the bookmaker's margin, the true probabilities with the margin removed, and the fair odds.
Result
| Outcome | Odds | True chance | Fair odds |
|---|
What is the bookmaker margin?
Turn each price into a probability (100 ÷ odds) and add them up. A fair book adds up to exactly 100%; real prices add up to more. The extra is the margin: the bookmaker's built-in fee. For 2.10 / 3.40 / 3.60 the implied chances are 47.6% + 29.4% + 27.8% = 104.8%, so the margin is 4.8%.
How fair odds are calculated
Each implied probability is divided by the total (104.8% in the example), which removes the margin proportionally. The result is the true chance of each outcome according to that price, and 100 ÷ true chance gives the fair odds. OddsEdge does this with the sharpest market's prices, then looks for bookmakers offering more than the fair odds.
Lower margins mean better prices for you. Comparing the margin across bookmakers for the same match is a quick way to see who prices it most generously. Step by step in How to calculate fair odds.