Introduction
An arbitrage bet happens when you place wagers on every possible outcome of a game or event using odds from different sportsbooks. If the odds are right, you lock in a profit no matter who wins. This is called an arbitrage opportunity, and it exists when the combined implied probability of all outcomes adds up to less than 100%.
Our free Arbitrage Calculator helps you find these opportunities fast. Enter the odds from each sportsbook, set your total stake, and the tool does the rest. It tells you exactly how much to bet on each outcome, shows your guaranteed profit, and breaks down the math step by step. You can use American, decimal, or fractional odds, and the calculator supports up to 16 outcomes at once. It even accounts for exchange commission if you bet on a platform that charges one.
Whether you are new to sports betting or already familiar with arbitrage strategies, this calculator makes it easy to spot profitable bets and divide your money the right way across every leg.
How to Use Our Arbitrage Calculator
Enter your odds from different sportsbooks and your total budget. The calculator will tell you if an arbitrage opportunity exists, how much to bet on each outcome, and your guaranteed profit.
Odds Format: Pick the odds format you want to use. Choose American (e.g., +150 or -110), Decimal (e.g., 2.50), or Fractional (e.g., 5/2). The calculator will convert your odds if you switch formats. If you need help converting between decimal and fractional formats, you can use our Decimal to Fraction Calculator. For a deeper look at how different odds formats relate to each other, try our Betting Odds Calculator.
Number of Outcomes: Set how many possible outcomes the event has. Most bets have 2 outcomes, but some markets like soccer or racing can have 3 or more. Use the dropdown, or click "Add Outcome" and "Remove Last" to adjust.
Outcome Label: Give each leg a name so you can keep track of your bets. This is optional. For example, you might type "DraftKings – Team A" or "FanDuel – Team B."
Odds: Type in the odds for each outcome. Each leg should come from the sportsbook that offers the best price for that outcome. The format must match the odds format you picked above.
Commission %: If you are using a betting exchange that charges a fee on winnings, enter the commission rate here. For regular sportsbooks, leave this at 0.
Total Stake: Enter the full amount of money you want to spread across all outcomes. The calculator splits this amount for you so that every outcome returns the same payout.
Click Calculate to see your results. You will get a breakdown of how much to stake on each leg, your guaranteed payout, profit, ROI, and a step-by-step explanation of the math. Click Reset to clear all inputs and start over.
What Is Arbitrage Betting?
Arbitrage betting is a strategy where you place bets on every possible outcome of a game or event, using different sportsbooks, so you are guaranteed a profit no matter who wins. This works when the odds across different bookmakers are different enough that the combined implied probability drops below 100%.
Think of it this way: one sportsbook might give better odds on Team A, while another gives better odds on Team B. If the gap between them is large enough, you can bet on both sides and lock in a sure profit. This gap is the arbitrage opportunity. To evaluate the size of individual bets and their payouts, our Bet Calculator is a handy companion tool.
How Does This Arbitrage Calculator Work?
This calculator takes the odds from each sportsbook you are comparing and checks if an arbitrage opportunity exists. If it does, it tells you exactly how much money to place on each outcome so your payout is the same no matter which side wins. It splits your total stake across each bet in the perfect ratio.
You can enter odds in American, decimal, or fractional format. The calculator also lets you add an exchange commission percentage for each leg, which is useful if you are using a betting exchange that takes a cut of your winnings. To understand how odds translate into fair probabilities without a bookmaker's margin, check out our No Vig Calculator.
Key Terms to Know
Implied probability is the chance of an outcome happening based on the odds. You find it by dividing 1 by the decimal odds. When you add up the implied probabilities of all outcomes, a total below 100% means an arbitrage opportunity exists. A total at or above 100% means the bookmaker has a built-in edge, often called the vig or hold. For general probability calculations, our Probability Calculator can help you work through the math.
ROI (Return on Investment) shows how much profit you earn as a percentage of the total amount you bet. In arbitrage betting, the ROI is usually small — often between 1% and 5% — but the profit is guaranteed, which is what makes it valuable. You can explore ROI in other contexts using our ROI Calculator.
Tips for Arbitrage Betting
- Act fast. Odds change quickly. An arbitrage window can close in minutes or even seconds. Use our Odds Calculator to quickly compare and convert odds across formats.
- Use multiple sportsbooks. You need accounts at several bookmakers to find and place arbitrage bets.
- Watch for limits. Some sportsbooks may limit or ban accounts that consistently win through arbitrage.
- Account for commissions. Betting exchanges charge a fee on winnings. Always include this in your calculations, or your guaranteed profit may disappear.
- Double-check your entries. A single wrong number can turn a sure profit into a loss. Use our Percentage Calculator to verify implied probabilities if you want an extra layer of confidence.
- Explore related strategies. If you are interested in multi-leg wagers beyond arbitrage, our Parlay Calculator and Round Robin Calculator can help you analyze combined bets across multiple games.
- Understand expected value. Arbitrage guarantees a positive expected value by design. To evaluate expected value in other betting or investment scenarios, try our EV Calculator.