Arbitrage Calculator Explained | OddsGuard
Split stakes across two sportsbooks to calculate guaranteed arbitrage return.
By OddsGuard Editorial · Published
Short answer
An arbitrage ("arb") occurs when two sportsbooks disagree enough that betting both sides locks in a small profit regardless of the result. True arbs are rare, small, and short-lived, and books may limit accounts that take them often.
How to spot an arbitrage
Add up the implied probabilities of the best available price on each side across different sportsbooks. When the combined total drops below 100%, an arbitrage opportunity exists.
Worked example
- Book A offers Team 1 at +110 (decimal 2.10, implied probability 47.62%).
- Book B offers Team 2 at -105 (decimal 1.952, implied probability 51.22%).
- Combined implied probability = 98.84% (under 100%, so it is an arb).
- To split $100 so both outcomes return the same amount, stake $48.18 on Team 1 and $51.82 on Team 2. Either result returns $101.18 — a $1.18 profit (about 1.2%).
The real-world risks
- Prices move quickly: if one side shifts after you place the first leg, the guaranteed profit can vanish.
- Bet limits and voids: a sportsbook may cap your maximum stake or void a wager placed on a palpable pricing error.
- Account restrictions: books frequently limit accounts that repeatedly target mispriced lines.
- Different house rules: verify both books grade the market identically (overtime included, push/void rules, retired players).
Frequently Asked Questions
Yes. Placing both sides of a market at different licensed sportsbooks is legal, though each sportsbook's terms and stake limits still apply.
OddsGuard compares live odds across 75 sportsbooks so you can immediately see when two books are far apart on the same matchup.
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