Free calculator
Arbitrage calculator
Enter the two prices and what you want to stake. You'll see the exact split, what each side returns, and the edge at those odds.
Side A
Side B
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Enter two prices to see the split.
Figures apply only at the odds you entered. Prices move, and an arbitrage only exists while both are still on the board.
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Scanning two books by hand is slow, and the gap is usually gone before you finish the math. BetSuite watches your sportsbooks and lines up both sides for you to review and place.
Download Free →How the math works
Every price carries an implied probability. American odds of +120 imply a 45.5 percent chance; -105 implies 51.2 percent. Add them together and you get 96.7 percent. That missing 3.3 percent is the gap between what the two sportsbooks believe, and it is the whole basis of an arbitrage.
When the two implied probabilities add up to less than 100 percent, you can back both outcomes and receive the same amount whichever way the game goes. That pairing of prices is a surebet. The calculator splits your stake in proportion to each side's implied probability so both returns land on the same number.
When they add up to more than 100 percent, the extra is the sportsbook's margin, the vig. That is the normal state of affairs, and it is why most pairs of odds are not arbitrage.
Arbitrage mode versus hedge mode
Use split a new stake when you have both prices in front of you and have not bet yet. You tell it your total budget, it tells you how to divide it.
Use hedge a bet I placed when one side is already down. Your first stake is fixed, so the calculator solves for the stake on the other side that evens out your return. This is what people do when a bet is winning and they want to bank part of it, or when they want to cut a loss.
What this calculator will not tell you
- Whether the odds still exist. Lines move in seconds. The most common failure is placing one side and finding the other has moved.
- Whether the bet will be honored. Sportsbooks void obvious pricing errors, and limits can stop you staking the full amount.
- Whether your account is at risk. Books limit customers they consider sharp. Read our guide on staying under the radar.
Arbitrage still works. The number on this page is just a snapshot at the prices you typed, not a promise about what happens next. If you're new to this, start with arbitrage betting 101, or compare where the prices tend to differ on our sportsbook comparisons.
Common questions
How does an arbitrage calculator work?
It converts both sets of odds into implied probabilities. If those probabilities add up to less than 100 percent, the two books disagree enough that backing both outcomes returns the same amount whichever side wins. The calculator splits your stake so each side returns that same figure, and shows the edge as a percentage of your total stake.
What is a good arbitrage percentage?
Most arbitrage opportunities on mainstream sportsbooks fall between 1 and 3 percent of the total stake. Larger gaps exist but are rarer, tend to appear on less liquid markets, and disappear faster. The percentage the calculator shows applies only at the odds you entered.
Why did my numbers change before I placed both bets?
Odds move. An arbitrage exists only while both prices are still available, so if one side moves after you place the first bet, the split you calculated no longer applies. This is the single most common way an arbitrage turns into an ordinary one-sided bet.
What is the difference between arbitrage and hedging?
Arbitrage means placing both sides at once, at prices you have already seen. Hedging means you already hold one bet and are covering the other side afterwards, often to lock in part of a win or cut a loss. The math is the same; only the timing differs. Hedge mode in this calculator holds your existing stake fixed and solves for the other side.