Free calculator
Arbitrage calculator
Enter the best available odds for each outcome and how much you want to stake in total. The calculator splits the stake so every result pays the same and shows the locked-in profit, or the loss if the prices are not an arbitrage.
Arbitrage found. Staking as above returns 104.22 whichever outcome wins.
Runs entirely in your browser; nothing you type is sent anywhere. For information only: PinnRadar sells odds data, takes no bets and gives no betting advice.
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Get a free key →The arbitrage formula
- Implied total
S = 1/o₁ + 1/o₂ (+ 1/o₃). An arbitrage exists whenS < 1. - Stake on outcome i = total × (1/oᵢ) / S
- Return on any outcome = total / S
- Profit = total / S − total, and ROI = 1/S − 1
Why arbs appear, and why they close fast
Bookmakers copy each other, and the market they watch most is Pinnacle. When Pinnacle moves and a slower book has not followed yet, the two prices can briefly cross. That gap is the arbitrage, and it lasts only until the slow book updates. Speed is the whole game: the Pinnacle odds dropper shows how often and how far those moves happen.
Finding them in code
Arbitrage scanners compare many books at once. The PinnRadar WebSocket API pushes each Pinnacle price change as it happens, so your scanner sees the sharp side of the gap within milliseconds. To judge single prices without a second book, compare them with the fair price from the no-vig calculator.
Questions people ask
What is arbitrage betting?
Backing every outcome of an event at different bookmakers when their prices disagree enough that the implied probabilities add up to less than 100%. Staked in the right proportions, every result returns the same amount, which is more than the total staked.
How are the arbitrage stakes calculated?
Each stake is the total stake times that outcome's implied probability (1 / odds), divided by the sum of all implied probabilities. Every outcome then returns total stake / sum, so the profit is the same whichever side wins.
How do I know if odds are an arbitrage?
Add up 1 / odds for the best price on each outcome. Below 1 (100%) is an arbitrage; the gap is your return. For example 2.12 and 2.05 give 47.2% + 48.8% = 96.0%, a return of about 4.2% on the total stake.
What are the risks?
Prices can move before every leg is placed, a bookmaker can void or limit a bet, and rules can differ between books (for example how retirements in tennis are settled). Check the rules and place the leg most likely to move first.
Where do sharp prices for arbitrage come from?
Arbitrage usually appears when a soft bookmaker is slow to follow a sharp one. The PinnRadar API streams Pinnacle's prices live, which tools can compare against other books to spot those gaps quickly.
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Feed these numbers from code
Live and prematch Pinnacle prices over REST, WebSocket and SSE, with no-vig prices and drop alerts built in. Compare the plans, or start on a free key.