Arbitrage betting calculator
An arbitrage bet, or arb, is when two sportsbooks disagree enough about a game that you can bet every outcome, one at each book, and get paid the same amount whichever side wins. This calculator tells you whether a set of prices is an arb and splits your stake so the payout is equal on every outcome.
It takes American or decimal odds, handles two-way markets such as moneylines, spreads and totals as well as three-way markets such as soccer with the draw, and can show a leg in Canadian dollars when that book is Canadian.
Free, no account needed. Everything is worked out in your browser and nothing you type is saved.
How to use the arbitrage calculator
- 1Enter the odds for one side at the first sportsbook and the opposite side at a second book. Switch between American (+150) and decimal (2.50) with the toggle above the calculator.
- 2For a three-way market, enter the third outcome in Side 3. Leave it blank for a two-way market.
- 3Set the total stake: the amount you want to put down across all legs combined.
- 4Read the margin. A negative margin is an arb, and the stake for each leg and the guaranteed profit appear beside it. A positive margin means the books still have an edge.
Worked example: +150 against -130
Book A prices a team at +150 and Book B prices their opponent at -130. You have $1,000 to put down. These are the numbers the calculator loads with.
- Implied probability at +150
- 40.00%
- Implied probability at -130
- 56.52%
- Combined
- 96.52% (margin -3.48%)
- Stake at Book A (+150)
- $414.41
- Stake at Book B (-130)
- $585.59
- Payout whichever side wins
- $1,036.04
Either result pays $1,036.04 back on the $1,000 staked, a guaranteed profit of $36.04, or 3.6%. Arbs this wide are uncommon and close quickly; most are a percent or two.
Frequently asked questions
How do I know if odds are an arbitrage?
Convert each price to its implied probability and add them up. A total under 100% is an arb, and the gap is your margin. +150 is 40% and -130 is 56.52%, 96.52% in total, so that pair is a 3.48% arb. The calculator shows this as a negative margin.
How are arbitrage stakes calculated?
Each leg gets a share of the total in proportion to its implied probability, which makes every outcome return the same amount. With two legs, stake 1 = total ÷ (1 + decimal odds 1 ÷ decimal odds 2), and the rest goes on side 2.
Can I use it for three-way markets like soccer?
Yes. Enter the home, away and draw prices in the three odds boxes. The calculator adds all three implied probabilities and splits the stake so each outcome pays the same.
Is arbitrage betting legal?
Betting at licensed sportsbooks is legal where they operate, and betting both sides of a game breaks no law. Sportsbooks can still limit stakes on accounts they see arbing, which is the practical risk.
What can go wrong with an arb?
A price can move before you place the second leg, a book can void or limit one leg, and two books can settle the same market differently, for example on overtime or a retired player. Place the harder-to-get leg first and check both books grade the market the same way.
Free now, free for good
Every BreadSync calculator is free to use without an account, and that is not changing. They work on the odds you type in.
Arbs close in minutes, so finding them by hand is slow. BreadSync Pro scans 130+ sportsbooks and surfaces arbs and low holds as the lines move.
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21+. Worked examples are illustrative and use made-up prices; real odds change constantly. Calculator results are estimates for information only, not betting advice or a guarantee of profit. BreadSync is not a sportsbook and does not accept wagers. If gambling stops being fun, call 1-800-GAMBLER.