An arbitrage (or "sure bet") exists when the implied probabilities of every outcome across different sportsbooks add up to less than 100%. Enter up to 4 outcomes in American odds plus your total stake — we'll tell you if an arb exists and exactly how much to bet on each side. Last updated: May 2026.
| # | American Odds | Implied % | Stake | Payout |
|---|---|---|---|---|
| 1 | — | — | — | |
| 2 | — | — | — | |
| 3 | — | — | — | |
| 4 | — | — | — |
Arbitrage is placing bets on every possible outcome of an event across different sportsbooks at prices that guarantee a profit regardless of which outcome wins. It exists because books disagree.
Convert every outcome's American odds to decimal, then sum 1 ÷ decimal_odds for all outcomes. If the total is less than 1.0 (100%), an arb exists. The smaller the sum, the bigger the guaranteed edge.
For each outcome, stake = (total_stake ÷ decimal_odds) ÷ arb_sum. This equalizes the payout no matter which outcome hits, leaving a fixed guaranteed return.
Yes, in jurisdictions where sports betting itself is legal. However, sportsbooks routinely limit or close accounts of bettors they detect using arbitrage strategies.
Books adjust lines constantly. Most arbs disappear within minutes as books rebalance their books or copy each other's prices. You need to act quickly and accept that some opportunities will close before you place all your bets.