Margin Calculator

Enter the book's odds on every outcome of a market and see the margin — the overround the book builds in. A fair market sums to 100%; everything above that is the house edge.

FREEMoney math

HIDDEN MARKET TAX

Enter bookmaker odds above to reveal the margin

1. MARKET INPUTS

Market type

Use decimal odds (e.g. 1.91). For 2-way markets only.

Enter bookmaker odds above to reveal the margin

Guide

Everything you need to use this tool with confidence.

Watch the 2-minute walkthrough

The Margin Calculator calculates a bookmaker's margin and shows you how much profit margin is built into a market.

Bookmakers fundamentally do not offer odds at the fair probabilities. Instead, a margin is built in that secures the bookmaker's profit over the long term.

With this calculator you can quickly see how high this margin is and how efficiently a market has been priced.

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