Arbitrage Calculator
Find guaranteed profit opportunities by entering odds from two different sportsbooks for opposing outcomes.
Stake on A
$49.40
Stake on B
$50.60
Guaranteed Profit
$3.73
ROI
3.73%
Bookmaker Margin
-3.60%
What Is Arbitrage Betting?
Arbitrage betting (or "arbing") exploits odds differences between sportsbooks to guarantee a profit regardless of outcome. An arb exists when the implied probabilities of all outcomes sum to less than 100%.
Formula: If (1/OddsA + 1/OddsB) < 1, an arbitrage opportunity exists. The margin below 100% is your guaranteed profit percentage.
Frequently Asked Questions
What is arbitrage betting?
Arbitrage means backing every outcome of an event at different books whose combined implied probability is below 100%, which locks in a profit no matter the result.
How do I know if an arb exists?
Add the implied probabilities (1 divided by decimal odds) of all outcomes. If the total is below 100%, there is an arbitrage, and the lower the total, the bigger the guaranteed margin.
How do I split my stake across an arb?
Stake each outcome in proportion to its implied probability so every result returns the same amount. This calculator works out each stake and your locked-in profit.
Is arbitrage betting legal?
Arbitrage is legal, but books may limit or close accounts they identify as arbing. Margins are small and odds move fast, so execution speed matters.
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