Arbitrage (Arb) Calculator

An “Arbitrage Bet” (or “Sure Bet”) is a risk-free opportunity to guarantee a profit by betting on all possible outcomes of an event across different bookmakers.

How It Works:

This is possible when bookmakers have different opinions (odds) on an event, creating a small window of opportunity. This calculator is for a 2-way market (e.g., Tennis Match Winner, Over/Under 2.5 Goals).

How to Use:

• Fixed Total Stake: The total amount of money you want to bet across *all* outcomes (e.g., £100).
• Outcome A Odds: The (high) odds for one outcome at Bookmaker 1.
• Outcome B Odds: The (high) odds for the *opposing* outcome at Bookmaker 2.

An “arb” exists if the **Combined Percentage** (the sum of the implied probabilities) is **less than 100%**. If it’s over 100%, it’s a standard “overround” and you will lose money.