Arbitrage Calculator
Enter odds from different bookmakers to check for arbitrage and calculate stakes.
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What Is Arbitrage Betting?
Arbitrage betting exploits differences in odds between bookmakers to guarantee a profit regardless of the outcome. It works when the implied probabilities across all outcomes sum to less than 100%.
To check for arbitrage: convert all odds to decimal, sum 1/odds for each outcome. If the total is less than 1, arbitrage exists and the difference is your profit margin.
Sports betting arbitrage (arbing) exploits different odds from different bookmakers on the same event, guaranteeing a profit regardless of outcome. For a two-outcome event, arbitrage exists when: (1/odds1) + (1/odds2) < 1. The sum represents the bookmakers' implied probability — if below 100%, a guaranteed profit exists.
Example: Bookmaker A has Team X at 2.10 (47.6%), Bookmaker B has Team Y at 2.30 (43.5%). Sum = 91.1% < 100% — arbitrage exists. Profit margin = 1 − 0.911 = 8.9%. To guarantee $100 profit on any outcome: stake on A = (total stake × 1/odds_A) / (1/odds_A + 1/odds_B). Solve for each side: if $1,000 total, stake $524 on A, $476 on B. Profit = $524 × 2.10 − $1,000 = $100.4 regardless of outcome.
Limitations and risks: arbitrage opportunities close within minutes as bookmakers adjust lines. Account limitations and closures are common — books identify arbers by patterns and restrict maximum stakes or close accounts. Execution risk (one leg placed, odds change before the other) can turn an arbitrage into a loss. Withdrawal delays can tie up funds.
Legal and ethical note: arbitrage is legal in most jurisdictions but violates the terms of service of many sportsbooks. Books reserve the right to void bets or limit accounts. Approach with awareness that accounts will eventually be limited.
Educational purposes only. Problem gambling: NCPG 1-800-522-4700.
See also: Implied Probability Calculator · Kelly Criterion Calculator