Arbitrage Betting Calculator
Find guaranteed profit by placing bets on all outcomes across different bookmakers. Use this when odds across sportsbooks create a combined implied probability below 100%.
About this calculator
Arbitrage betting exploits pricing differences between bookmakers so that, regardless of which outcome wins, you profit. The key check is whether the sum of implied probabilities across all outcomes is less than 1: if (1/odds1) + (1/odds2) < 1, an arb exists. Your guaranteed profit is calculated as: profit = totalStake × (1 / ((1/odds1) + (1/odds2)) − 1) × (1 − commission/100). The term 1 / ((1/odds1) + (1/odds2)) is often called the arb multiplier. Commissions from exchanges like Betfair reduce this margin and must be factored in. If no arb exists, the formula returns 0, signaling no opportunity is present.
How to use
Suppose Bookmaker A offers 2.10 on Team A winning and Bookmaker B offers 2.05 on Team B winning. Check the arb: (1/2.10) + (1/2.05) = 0.476 + 0.488 = 0.964 — less than 1, so an arb exists. With a $1,000 total stake and 0% commission: profit = $1,000 × (1/0.964 − 1) = $1,000 × 0.0373 = $37.30. You stake $476 on Team A and $524 on Team B. Either way, you collect roughly $1,037, netting $37.30 guaranteed profit.
Frequently asked questions
What does it mean when the arbitrage calculator shows zero profit?
A result of zero means no true arbitrage opportunity exists with those odds. This happens when the combined implied probability — (1/odds1) + (1/odds2) — equals or exceeds 1.0, meaning the bookmakers' margins overlap and all outcomes cannot be covered profitably. You should either find better odds at alternative bookmakers or skip that market entirely. Even a combined probability of exactly 1.0 yields breakeven, not profit.
How does commission affect my arbitrage profit?
Exchange commissions, typically 2–5%, are deducted from your winnings and directly reduce arb profit. The formula multiplies the raw profit by (1 − commission/100), so a 5% commission on a $37 gross profit leaves only about $35.15. High commission rates can eliminate thin arb margins entirely, turning a theoretical opportunity into a loss. Always enter your actual exchange commission before deciding whether to place the bet.
Why do sportsbooks limit or ban arbitrage bettors?
Bookmakers lose money on arbitrage bettors because they consistently extract profit regardless of outcome. Sportsbooks monitor accounts for patterns such as always betting at maximum stakes on obscure markets or rapidly placing bets when odds are mispriced. Detected arbers often have their stakes limited to very small amounts or accounts suspended. Many experienced arbers use multiple accounts, bet within normal-looking limits, and avoid extreme stake precision to extend account longevity.