Arbitrage (Surebet) Calculator
Advertising
How to use this calculator
Choose a two or three-outcome market, then enter the best available odds for each outcome - usually from different bookmakers. Add your total stake and the calculator splits it across the outcomes so every result returns the same amount. If the combined market sits under 100%, there is an arbitrage and the split locks in a guaranteed profit. If it sits over 100%, no surebet exists and the tool shows how close the market is. The stake breakdown gives the exact amount to place on each outcome.
The terms, explained
- Arbitrage (surebet) - backing every outcome of a market at different books so you profit no matter what happens.
- Market total - the sum of every outcome's implied probability. Under 100% means an arb; over 100% is the bookmakers' margin.
- Stake split - how to divide your total stake so each outcome returns the same amount.
- ROI - your guaranteed return on the total invested. A 2-3% surebet is typical; larger ones are rare and often disappear fast.
How it is calculated
The whole thing rests on implied probabilities, so the maths never changes - only the odds you feed in do.
- Market total
total = 1÷odds₁ + 1÷odds₂ (+ …) - Arbitrage exists when
total < 1 - Stake on an outcome
stakeₐ = total stake × (1÷oddsₐ) ÷ total - Guaranteed return
return = total stake ÷ total
Because every outcome is staked to return the same figure, the profit is identical no matter which result lands.
Surebets are real but hard to keep. The edges are small and short-lived, odds move while you are placing the second leg, and bookmakers limit or close accounts that arb consistently. Stake limits, minimum bets and rounding can also erode a thin margin, and a voided or mis-graded leg can turn a "guaranteed" profit into a loss. Treat the numbers here as the ideal case and account for real-world friction before relying on them.
For information only. This is not betting advice. 19+ (18+ in AB, MB and QC). Please play responsibly.