Vig Calculator
Calculate the sportsbook’s built-in margin for a given market
The Vig Calculator measures the sportsbook’s built in margin, also known as the overround or hold, in a betting market. Sportsbooks price both sides of a market so that the total implied probability exceeds 100 percent. The difference above 100 percent represents the bookmaker’s edge.
By entering the odds for each side of a two outcome market, the calculator converts them into implied probabilities and sums them together. The amount above 100 percent is the vig percentage, which indicates how expensive the market is for bettors.
For example, if two sides of a market are both priced at -110, their implied probabilities combine to approximately 104.8 percent. That extra percentage reflects the sportsbook’s margin. Markets with higher overrounds are generally less efficient and more costly to bet into.
Understanding vig helps you compare pricing quality across sportsbooks. Lower hold percentages typically mean tighter, more competitive markets, while higher hold percentages suggest more built in edge for the book. Measuring vig is an important step in evaluating where to place your bets.