Bookmaker Margin Calculator
Bookmaker margin, sometimes called the vig or juice, is the built-in edge a book keeps by pricing a market's outcomes to sum to slightly more than 100% implied probability.
How it works
Add up the implied probability of every outcome in the market. Anything above 100% is the bookmaker's margin - the structural cost of betting into that market, regardless of which side you pick.
Worked example: A two-way market priced at 1.91 and 1.91: 52.4% + 52.4% = 104.8%, a 4.8% margin.
FAQ
Is a lower margin always better for the bettor?
Yes, all else equal - a lower margin means the odds are closer to the market's true probabilities, leaving less structural edge for the book.
Does margin vary by sport or market type?
Significantly. Mainstream markets like major-league match winners tend to carry lower margins than exotic or low-volume markets.
Related tools
18+. These tools are analytical only - they do not accept bets, do not predict outcomes, and do not guarantee profit. Gamble responsibly. Sports betting regulations vary by jurisdiction; you are responsible for understanding and complying with the laws where you live.
Canonical URL: https://aipredicts.bet/tools/bookmaker-margin-calculator