Bookmaker Margin / Vigorish Calculator

Bookmaker margin calculator screenshot

A Bookmaker Margin / Vigorish Calculator has been added to the Online Calculators area of the Tools section.

The tool calculates the bookmaker margin (overround) and vigorish (vig) for a set of entered odds. Arbitrage opportunities are highlighted if they exist. All major odds formats such as decimal, fractional and American are supported. The calculator works for up to 24 selections to enable it to cater for racing win markets.

View the calculator

What Are Bookmaker Margins?

The bookmaker margin, also known as the overround, the cut or the take, is the hidden amount charged by a bookmaker for accepting a wager.

The bookmaker margin is a measure of the bookmaker’s profit margin for an event and is a hidden transaction cost for punters. This profit is how bookmakers finance their services but bookmakers vary in the margins they apply. From a punter’s perspective, the lower the margin, the better.

By joining more than one bookmaker, punters can lower the effective margins by shopping around for odds. In some circumstances the combined bookmaker margin can be negative, which indicates an arbitrage opportunity exists.

Unfortunately there are conflicting definitions of bookmaker margin and vigorish. Even on Wikipedia the explanation of how to calculate vigorish depends on which article you visit. This calculator uses the definition of bookmaker margin (overround) as used in the Mathematics of bookmaking Wikipedia article and the definition of vigorish as used in the Vigorish Wikipedia article.

Related Resources


Share this:


Post Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.