Arbitrage Betting Calculator
Find guaranteed profit by placing bets on all outcomes across different bookmakers. Use this when the combined implied probabilities from two or more books sum to less than 100%.
About this calculator
Arbitrage (or 'sure bet') occurs when the implied probabilities across all outcomes at different bookmakers sum to less than 1 (100%). The total implied probability is: impliedProb = (1 / odds1) + (1 / odds2). If impliedProb < 1, an arb exists. The guaranteed profit on a total stake S is: Profit = S × (1 − impliedProb). To split your stake optimally, allocate to each leg proportionally to 1/odds divided by the total implied probability, ensuring equal returns regardless of outcome. For example, if odds1 = 2.10 and odds2 = 2.10, impliedProb = 0.476 + 0.476 = 0.952 < 1, giving a ~5% guaranteed return. Always account for platform withdrawal fees and bet limits, which can erode arb profits.
How to use
Say Bookmaker 1 offers Team A at decimal odds 2.10 and Bookmaker 2 offers Team B at 2.20, with a total stake of $1,000. Step 1 — Enter odds1 = 2.10, odds2 = 2.20, totalStake = $1,000. Step 2 — impliedProb = (1/2.10) + (1/2.20) = 0.4762 + 0.4545 = 0.9307. Step 3 — Since 0.9307 < 1, an arb exists. Step 4 — Profit = $1,000 × (1 − 0.9307) = $69.30 guaranteed. Step 5 — Stake on Team A = $1,000 × (0.4762 / 0.9307) ≈ $511.60; the remainder on Team B.
Frequently asked questions
How do I find arbitrage betting opportunities between sportsbooks?
Arbitrage opportunities arise when competing bookmakers price the same event differently enough that the sum of implied probabilities falls below 100%. You can find them by monitoring odds across multiple books simultaneously, using odds-comparison websites, or subscribing to arb-finder software. They are most common around major sporting events when books update lines at different speeds. Act quickly — arbs typically close within minutes as books adjust their lines.
What is the minimum profit margin worth pursuing in arbitrage betting?
Most experienced arb bettors target margins of at least 1–2% after accounting for transaction costs such as payment processing fees, currency conversion, and withdrawal charges. Margins below 1% are often wiped out by these costs or by bookmakers voiding suspicious bets. A 2–5% arb on a $1,000 stake yields $20–$50 risk-free, which becomes worthwhile at scale but requires significant bankroll management.
Why do bookmakers limit or ban arbitrage bettors?
Sportsbooks are profit-driven businesses and arb bettors represent a guaranteed loss for them. When a book consistently takes the 'wrong' side of a mispriced market, it flags the account for review. Books use pattern detection — unusually high bet amounts placed immediately after line movements, always on the side that changes, are telltale signs. Accounts identified as arb bettors are typically limited to very small stakes or banned outright, making it important to vary bet sizing and timing.