# Arbitrage Calculator

## How to Use Our Arbitrage Calculator

To use our arbitrage calculator to find whether an arbitrage opportunity exists, how much to bet, and your profit:

- Select your odds format (American, decimal, fractional, etc.)
- Enter the odds for one outcome of the arbitrage opportunity in the "Odds #1" input.
- Enter your bet amount for the first outcome in the "Bet Amount #1" input.
- Enter the odds for the other outcome of the arbitrage opportunity in the "Odds #2" input.

After you enter valid odds and a bet amount, the calculator will automatically output how much you should bet to maximize profit, given your first bet amount. It will also show your total profit and ROI for the arbitrage.

## What is Arbitrage Betting?

Arbitrage betting is when a bettor places wagers on multiple outcomes of an event to guarantee a profit. Each bet is usually placed at a different sportsbook. For example, a bettor may place a bet that Team A will beat Team B on Sportsbook A and another bet that Team B will beat Team A on Sportsbook B.

Arbitrage opportunities exist because each sportsbook is responsible for setting their odds for a given market. An arbitrage opportunity can exist if there's a large enough difference between two books' odds.

Differing odds among sportsbooks can exist because:

- Sportsbooks disagree about the odds for a given market.
- A sportsbook is slow to adjust its odds or take a market offline.
- A sportsbook makes an error setting their lines.

### Arbitrage Example

Let's look at a few arbitrage examples and how to use our calculator to see how much to bet and the profitability of the situation.

#### Simple Arbitrage Example

Before diving into a real profitable arbitrage I made, here is a super simple hypothetical arbitrage example:

- Book A has the Kansas City Chiefs at +110 odds (2.1 decimal odds, 11/10 fractional) to beat the Los Angeles Rams.
- Book B has the Los Angeles Rams at +110 odds to beat the Kansas City Chiefs.

We enter the Chief's +110 odds in the "Odds #1" input of the arbitrage calculator, a $100 bet in the "Bet Amount #1" input, and the Ram's +110 odds in the "Odds #2" input.

The arbitrage calculator shows:

- Given a $100 bet on the Chiefs at +110, I should bet $100 on the Rams at +110.
- If I place both these wagers, I'll guarantee a profit of $10.
- Betting $100 on each side makes the total amount bet $200. With $10 of profit, this is a +5% ROI.

#### Example of a Real Arbitrage I've Made

Below is a real arbitrage opportunity I was able to take advantage of, though I'm replacing the bet amount with a round number for simplicity's sake:

- On Book A, the odds for the Memphis Grizzlies at a -11.5 point spread were +185 underdogs (2.85 decimal odds, 37/20 fractional odds) against the Los Angeles Lakers.
- On book B, the Los Angeles Lakers were -155 favorites (1.6452 decimal odds, 20/31 fractional) at a +11.5 point spread.

If I enter the Grizzlies' +185 odds in the "Odds #1" input, a $100 bet in the "Bet Amount #1" input, and the Laker's -155 odds in the "Odds #2" input:

- I'll see I should bet $173.24 on the Lakers -11.5 point spread at -155 odds, given a $100 bet on the Grizzlies at +185.
- This arbitrage will profit $11.77.
- Given our $11.77 profit and $273.24 total amount bet, our ROI will be +4.31%

#### Example of an Unprofitable Situation

In this final hypothetical example, we'll show how the arbitrage calculator can show you that a profitable arbitrage does not exist.

- Team A is -110 to beat Team B.
- Team B is -110 to beat Team A.

## The Risk of Arbitrage Betting

If you can place bets for the correct amounts on a true arbitrage opportunity and the sportsbooks honor your wagers, that's a risk-free bet with guaranteed profit. However, there are a few things to consider:

### Line Changes

Most arbitrage opportunities only exist for short periods. If you place one side of the arbitrage but aren't able to get in the other side before the odds change to an unprofitable level or the sportsbook takes the market offline, you're still on the hook for the original wager.

Personally, when betting arbitrage opportunities, I always bet the side with the most mispriced odds first. That makes it far more likely I'll be able to bet the other side at a profitable arbitrage.

Example:

- Team A has odds around -110 at most books, but Book X has them at +120.
- Team B has odds around -110 at most books, Book X at -155, and Book Z at -105.

The optimal arbitrage above is betting on Team A at +120 on Book X and then betting on Team B at Book Z at -105. Since Book X's odds on Team A differ more than Book Z's odds on Team B, I'd first bet Team A on Book X. If Book Z changes their odds, there's still a good chance I can get in a profitable arbitrage by betting Team B at -110 on another book.

However, there's no guarantee you'll be able to place both sides of an arbitrage before lines change or markets are taken offline. Your options are then to take the risk of the single bet you placed, cash out the bet if your book offers this feature (possibly at a loss), or make an unprofitable hedge to limit your potential losses.

### Sportsbooks Not Honoring Bets

At times, sportsbooks may cancel your bets. This is usually only done when the book makes a clear and obvious error setting their odds.

For example, say most books have Team A at -110 odds and Team B at -110 odds, but one book has Team A at +300 odds. If you try to arbitrage this clear error, it's very likely the book with the +300 odds will cancel your bet.

Less reputable or offshore books are more likely to cancel bets for various reasons.

### Getting Banned or Limited By Sportsbooks

While arbitrage is legal, sportsbooks don't like profitable bettors. If you're regularly making profitable bets, you're likely to get your account limited or entirely banned from betting at that sportsbook.

It's often recommended to use round numbers on sportsbooks whenever possible to avoid raising suspicion. In the Grizzlies vs. Lakers arbitrage example above, the calculator said to bet $173.24 on the Lakers. In that scenario, one could instead bet $175 and still be profitable (though a bit less so) while raising fewer red flags.

### It's Up to You to Manage Risk and Execute

As always, it's up to the individual to manage their own risk and correctly execute profitable betting strategies. There's always the possibility of user error or something out of their control taking place.