How to use the calculator
- The “Selection” column is optional and does not affect the calculation.
- Choose your preferred odds format; decimal, fractional or American.
- The odds for all possible outcomes must be included.
With the above calculator you can work out the book % and sportsbook’s overround for any betting market. This means you can check if a sportsbook is giving you good value odds and you can check whether arbitrage opportunities exist across different sportsbooks.
How much overround should there be?
The below table is for 2 selection betting markets. It’s normal for the overround to rise as the number of selections rise, because some overround has to be added to the odds of each selection.
|Negative||Arbitrage bet on all selections for guaranteed profit!|
|0% – 3.5%||Competitive good value odds|
|3.5% – 5%||Acceptable odds|
|5%-7%||Poor value odds, look elsewhere|
|Greater than 7%||A rip off!|
It is almost impossible to make long term profit if your sportsbook gives you odds with more than a 5% overround. See our best odds sportsbook rankings to find out if that is the case with your sportsbook.
Overround of 50/50 odds
A 50/50 bet is one that has an equal chance of winning or losing. Totals and spreads are often 50/50 markets. If there was no overround the odds would be 2. Below is the overround for different 50/50 odds.