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Arbitrage betting strategies involve placing wagers on both sides of the same game, with each bet made at a different sportsbook. The varying lines offered at different sportsbooks sometimes make it possible to use arbitrage bets that ensure player profit on a game, no matter what the outcome.

The Gaming Today Arbitrage Calculator allows you to input two or more lines at a time and instantly calculate the sportsbooks’ edge. If the effective bookmaker margin equals less than one, an arbitrage betting opportunity exists.

Highest Odds
Selection 1
Selection 2
Selection 3
Selection 4
Selection 5

Betting Outcomes

Strategies (Bet on Selection 1)

NoneNo BiasBiased
Selection 1
Selection 2
Selection 3
Selection 4
Selection 5

Using An Arbitrage Calculator For Moneyline Bets

Moneyline bets offer straight-up wagering on which team will win a game, with no point spread involved. The underdog on the moneyline pays out at better odds than the favorite.

When looking at the moneyline, the favored team is denoted by “-“ odds, while the underdog can be found by looking for the team with “+” in front of its odds. For “+” lines, the higher the number, the bigger the payoff. For “-“ odds, lower numbers indicate better payoffs.

The object of arbitrage betting is to find a way to bet on the favorite at one sportsbook while betting on the underdog at another. A successful arbitrage opportunity exists if you can find opposing lines that allow you to profit off the game no matter what.

Let’s take a look at a theoretical arbitrage opportunity, using Super Bowl LV as an example:

“Sportsbook A” Super Bowl LV Moneyline Odds

Kansas City Chiefs-160
Tampa Bay Buccaneers+140

“Sportsbook B” Super Bowl LV Moneyline Odds

Kansas City Chiefs-195
Tampa Bay Buccaneers+170

You can see if an arbitrage opportunity exists for this game by inputting the best line on each team into the “Highest Odds” field in the Gaming Today Arbitrage Calculator. In this example, the best line on Kansas City (-160) is offered by Sportsbook A. The better line on Tampa Bay comes from Sportsbook B, which offers (+170) odds on the Buccaneers.

Input -160 (Kansas City’s highest odds) on the “Selection 1” line, then +170 for “Selection 2” (Tampa Bay’s highest odds). Click the “Bias” column for the team you think has a better chance of winning, and be sure the “Include” row is checked off for each line you want to calculate.

For this example, we’ll input 100 in the “Total Wager ($)” field and calculate the arbitrage odds for a $100 bet. Inputting the best odds on both sides of this hypothetical bet, with bias toward Kansas City, yields this output from the arbitrage calculator:

How To Use The Data From The Gaming Today Arbitrage Calculator

The arbitrage calculator tells us that the bookmaker margin is 0.9858 in this scenario. Anything less than “1” indicates an arbitrage opportunity for the bettor.

In this case, you have a 1.45% profit opportunity from betting on the best odds on each team at the different sportsbooks. The first column (“None”) shows how you would fare by placing $100 on each side of the bet, and Kansas City (the “bias” team in this example) won the game.

That strategy won’t win in the long run, however, as you need to figure out how to break up your $100 bet to place the right amount of money on both sides of the bet.

The second column (“No Bias”) displays exactly how much you need to bet on each line to gain the maximum profit. For this example, you’d need to bet $62.43 on Kansas City (-160) and $37.57 on Tampa Bay (+170) to achieve the 1.45% profit, which you earn no matter which team wins.

The third column (“Bias”) shows the maximum you could bet on the team you’re biased toward thinking will win the game while ensuring at least a breakeven result if that team loses. In this example, you could bet a maximum of $62.96 on Kansas City and still break even if the Chiefs lose.

The Gaming Today Arbitrage Calculator can be used to evaluate an unlimited number of lines. Click the “Add Selection” bar to add another line. This feature can be used to evaluate futures bets or any other kind of wager with three or more lines.

Calculating Negative Moneyline Odds

US sportsbooks generally display lines using American odds, with “-“ in front of the favorite’s odds and “+” in front of the underdog’s odds.

To calculate “-“ odds, divide 100 by the odds (without the minus sign) and multiply that quotient by the amount of the wager.

A $50 bet on the Kansas City (-160) line, for instance, would calculate as (100/160)*50, which ends up as (0.625)*$50 and yields a solution of $31.25.

A winning $50 bet on the Kansas City (-160) lines would result in $81.25 total returned to the bettor ($31.25 profit plus the original $50 wager).

Calculating Positive Moneyline Odds

To calculate “+” American odds, divide the odds by 100 and multiply by the amount of the bet.

A $50 bet on Tampa Bay (+170), for instance, could be calculated as (170/100)*$50, which equates to (1.7)*$50 and gives us a solution of $85.

If a $50 bet on Tampa Bay (+170) was a winner, the wager would return $135 total to the bettor ($85 profit plus the original $50 wager.

For an easier way to calculate moneyline odds, check out Gaming Today’s Moneyline Calculator.

Line Movement And Arbitrage Betting

Arbitrage opportunities sometimes last only minutes, as sportsbooks change the lines based on how the public is betting.

Sportsbooks offer odds that aim to bring in enough money on both sides of the bet, allowing the house to profit no matter which team wins the game. If the public heavily favors one side of the bet, the house will start to shift the line the other way.

For example, the (+170) line on Tampa Bay in the above example might not last long, as the public could start putting big money down on the underdog Buccaneers at that price. If the odds on the Bucs go down to +160 or lower, the arbitrage opportunity no longer exists.

Legal Online Sports Betting In The US

More than a dozen states currently enjoy access to legal online sports betting. Michigan and Virginia became the most recent states to join the online sports betting industry, with both states launching mobile sports betting apps in January 2021.

The following states currently offer legal online sports betting:

States Offering Legal Online Sports Betting

Best Online Sportsbooks In The US

BetRivers Sportsbook

Named after the Rivers Casino brand, BetRivers functions as an online gambling platform operated by gaming giant Rush Street Interactive. BetRivers Sportsbook offers a selection of sports that’s almost unparalleled in the legal US market.

Bettors in New Jersey, Pennsylvania, Illinois, Indiana, Iowa, Colorado, Michigan, and Virginia can access BetRivers’ online sports betting services.

FanDuel Sportsbook

Bettors of all experience levels would do well to check out FanDuel Sportsbook for just about any sport. The selection of domestic, international, and niche sports at FanDuel Sportsbook puts the platform in an elite category in the US.

FanDuel Sportsbook currently offers online sports betting in ten states. That list includes New Jersey, Pennsylvania, Illinois, Indiana, Iowa, Colorado, West Virginia, Michigan, Tennessee, and Virginia.

DraftKings Sportsbook

DraftKings Sportsbook stands as one of the most recognizable brands in the US sports economy. Since expanding into sports betting, DraftKings has emerged as one of the most popular online sports betting sites in the nation.

DraftKings Sportsbook operates mobile sports betting in eleven states. Bettors in New Jersey, Pennsylvania, Illinois, Indiana, Iowa, Colorado, West Virginia, Michigan, Tennessee, Virginia, and New Hampshire can bet online at DraftKings Sportsbook.

Arbitrage Probability Calculator FAQs

Is online sports betting legal in the US?

Yes. A change in federal laws in May 2018 opened the door for US states to offer online sports betting.

Since that shift in law, more than a dozen states have given the green light for legal online sports betting. Some of the biggest online sports betting markets in the US include New Jersey, Pennsylvania, and Illinois.

When should I use an arbitrage calculator?

Arbitrage betting requires complex calculations if you want to use an optimal, long-term strategy. The Gaming Today Arbitrage Calculator can and should be used any time you want to evaluate an arbitrage opportunity.

Is it legal to use an arbitrage calculator?

Yes. Arbitrage calculators, along with the other calculator tools here at Gaming Today, can be used legally for any sports bet.

How do I convert American odds to fractional odds?

To convert  “+” American odds to fractional odds, divide the odds by 100 and change that output to a fraction. To convert +170 into fractional odds, for instance, divide 170 by 100 (170/100) and reduce that fraction to 17/10. In this case, +170 translates to 8/5 fractional odds.

To convert “-” American odds, divide 100 by the odds number (without the minus sign) and change that quotient to a fraction. For instance, -170 odds can be calculated as 100/170 and reduced to fractional odds of 10/17.

What is the best online sportsbook in the US?

FanDuel Sportsbook, DraftKings Sportsbook, BetRivers, BetMGM, and William Hill represent some of the best legal online sportsbooks in the US.

Several other excellent mobile sports betting platforms also operate across the US, including PointsBet, FOX Bet, Unibet Sportsbook, and Golden Nugget Sportsbook.

How do I convert American odds to implied probability?

To convert positive American odds to implied probability, you can use this formula:

100 / (“+” American odds + 100)*100 = implied probability

For example, +170 odds would be calculated as 100/(170+100)*100. This converts to 100/270*100, and we end up with a 37.03% implied probability.

To convert negative American odds, the formula looks like this:

“-” odds / (“-” odds + 100)*100 = implied probability

For instance, -160 odds would calculate as 160/(160+100)*100, and convert. to 160/260*100. This equation solves as 61.54, giving us an implied winning probability of  61.54%.

Gaming Today offers an Implied Probability Calculator that yields instant results for any odds input.

About the Author
Geoff Fisk

Geoff Fisk

Geoff Fisk is a San Diego-based freelance writer, specializing in the poker and gambling industries. He’s written for numerous platforms and has traveled the globe as a live poker tournament reporter. Geoff is an avid sports fan, but poker is his passion.

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