Free arbitrage calculator
Find the stakes that lock in a profit on any arb
Enter the odds from two books. The calculator splits your stake so every outcome pays the same, and you’ll see the profit before you bet.
How an arb works
Step 1
Find a price gap
Two books price the same game far enough apart that backing both sides costs less than the payout.
Step 2
Size each stake
Split the bankroll by each side’s implied probability so both outcomes return the same amount.
Step 3
Place both bets quickly
Prices can move within minutes, so get both legs down before either line changes.
How an arb works
Step 1
Find a price gap
Two books price the same game far enough apart that backing both sides costs less than the payout.
Step 2
Size each stake
Split the bankroll by each side’s implied probability so both outcomes return the same amount.
Step 3
Place both bets quickly
Prices can move within minutes, so get both legs down before either line changes.
How an arb works
Step 1
Find a price gap
Two books price the same game far enough apart that backing both sides costs less than the payout.
Step 2
Size each stake
Split the bankroll by each side’s implied probability so both outcomes return the same amount.
Step 3
Place both bets quickly
Prices can move within minutes, so get both legs down before either line changes.
Hedge, middle and odds conversion
Hedge, middle and odds conversion
Use the hedge calculator to protect an open bet, check a middle on a totals line, or convert odds between American, decimal and fractional.
Use the hedge calculator to protect an open bet, check a middle on a totals line, or convert odds between American, decimal and fractional.
Guides
The math and the practical side of arbing
What arbitrage betting is
How a fixed profit comes from two prices that disagree.
Arbitrage math
Implied probability, the 100% line and a worked example.
Stake sizing
How to split a bankroll and round stakes without giving up the edge.
Account limits
Why sportsbooks limit arbers and which betting patterns get noticed.
No-vig prediction markets
Why a low-vig price on one side makes arbs easier to find.
Legality in the US
What the law says about arbitrage betting, in broad terms.
Guides
The math and the practical side of arbing
What arbitrage betting is
How a fixed profit comes from two prices that disagree.
Arbitrage math
Implied probability, the 100% line and a worked example.
Stake sizing
How to split a bankroll and round stakes without giving up the edge.
Account limits
Why sportsbooks limit arbers and which betting patterns get noticed.
No-vig prediction markets
Why a low-vig price on one side makes arbs easier to find.
Legality in the US
What the law says about arbitrage betting, in broad terms.
Guides
The math and the practical side of arbing
What arbitrage betting is
How a fixed profit comes from two prices that disagree.
Arbitrage math
Implied probability, the 100% line and a worked example.
Stake sizing
How to split a bankroll and round stakes without giving up the edge.
Account limits
Why sportsbooks limit arbers and which betting patterns get noticed.
No-vig prediction markets
Why a low-vig price on one side makes arbs easier to find.
Legality in the US
What the law says about arbitrage betting, in broad terms.
Where to arb
Sportsbooks and no-vig prediction markets
Sportsbooks
About 4.8% hold on a -110/-110 line
Winning accounts often get limited
Prices set by one trading desk
Margin built into every price
No-vig prediction market
Little or no vig on either side
Bets are matched between users
Prices set by users posting orders
Prices sit close to fair odds
Sportsbooks
About 4.8% hold on a -110/-110 line
Winning accounts often get limited
Prices set by one trading desk
Margin built into every price
No-vig prediction market
Little or no vig on either side
Bets are matched between users
Prices set by users posting orders
Prices sit close to fair odds
Arbitrage betting questions
Short answers to the questions new arbers ask first.
01
What is arbitrage betting?
Arbitrage betting means backing every outcome of an event at different books when their prices add up to less than 100% implied probability. With the right stakes, every outcome returns the same amount, so the profit is set before the game starts.
02
How much does an arb make?
It depends on the prices. On $1,000 at +105 and +102, the calculator stakes $496 and $504 and locks in $16.80, a 1.7% return.
03
Is arbitrage betting legal?
Betting both sides of a game at licensed sportsbooks is legal wherever sports betting is legal. Sportsbooks can still limit or close accounts under their own terms. The legality guide covers this in more detail.
04
Why do sportsbooks limit arbers?
A sportsbook builds a margin into its prices. A bettor who only takes its off-market prices costs it money, so many books cut the stake limits on those accounts.
05
Do both bets need to go in at the same time?
As close together as you can manage. If one line moves before you’ve placed the second bet, the arb can turn into a loss. The hedge calculator shows the options when one leg is stuck.
06
Why use a no-vig prediction market for one side?
Vig widens the gap between the two sides of a market. Two sportsbooks that each hold about 4.8% have to disagree by more than that before an arb appears. A price with little or no vig on one side narrows that gap, so more arbs clear the 100% line.
Arbitrage betting questions
Short answers to the questions new arbers ask first.
01
What is arbitrage betting?
Arbitrage betting means backing every outcome of an event at different books when their prices add up to less than 100% implied probability. With the right stakes, every outcome returns the same amount, so the profit is set before the game starts.
02
How much does an arb make?
It depends on the prices. On $1,000 at +105 and +102, the calculator stakes $496 and $504 and locks in $16.80, a 1.7% return.
03
Is arbitrage betting legal?
Betting both sides of a game at licensed sportsbooks is legal wherever sports betting is legal. Sportsbooks can still limit or close accounts under their own terms. The legality guide covers this in more detail.
04
Why do sportsbooks limit arbers?
A sportsbook builds a margin into its prices. A bettor who only takes its off-market prices costs it money, so many books cut the stake limits on those accounts.
05
Do both bets need to go in at the same time?
As close together as you can manage. If one line moves before you’ve placed the second bet, the arb can turn into a loss. The hedge calculator shows the options when one leg is stuck.
06
Why use a no-vig prediction market for one side?
Vig widens the gap between the two sides of a market. Two sportsbooks that each hold about 4.8% have to disagree by more than that before an arb appears. A price with little or no vig on one side narrows that gap, so more arbs clear the 100% line.
Arbitrage betting questions
Short answers to the questions new arbers ask first.
01
What is arbitrage betting?
Arbitrage betting means backing every outcome of an event at different books when their prices add up to less than 100% implied probability. With the right stakes, every outcome returns the same amount, so the profit is set before the game starts.
02
How much does an arb make?
It depends on the prices. On $1,000 at +105 and +102, the calculator stakes $496 and $504 and locks in $16.80, a 1.7% return.
03
Is arbitrage betting legal?
Betting both sides of a game at licensed sportsbooks is legal wherever sports betting is legal. Sportsbooks can still limit or close accounts under their own terms. The legality guide covers this in more detail.
04
Why do sportsbooks limit arbers?
A sportsbook builds a margin into its prices. A bettor who only takes its off-market prices costs it money, so many books cut the stake limits on those accounts.
05
Do both bets need to go in at the same time?
As close together as you can manage. If one line moves before you’ve placed the second bet, the arb can turn into a loss. The hedge calculator shows the options when one leg is stuck.
06
Why use a no-vig prediction market for one side?
Vig widens the gap between the two sides of a market. Two sportsbooks that each hold about 4.8% have to disagree by more than that before an arb appears. A price with little or no vig on one side narrows that gap, so more arbs clear the 100% line.
Latest guides
Basics
What Is Arbitrage Betting?
Arbitrage betting backs every outcome at different books when their prices add up to less than 100%. How it works, a worked example and where to go next.
Latest guides
Basics
What Is Arbitrage Betting?
Arbitrage betting backs every outcome at different books when their prices add up to less than 100%. How it works, a worked example and where to go next.
Latest guides
Basics
What Is Arbitrage Betting?
Arbitrage betting backs every outcome at different books when their prices add up to less than 100%. How it works, a worked example and where to go next.
Run the numbers before you bet
The arbitrage calculator is free and doesn’t need an account.
Run the numbers before you bet
The arbitrage calculator is free and doesn’t need an account.
Run the numbers before you bet
The arbitrage calculator is free and doesn’t need an account.