Betting Margins

Sports betting margins show the odds difference between the price offered for a punter’s bet by the bookmaker and the actual probability of the game outcome. There are formulas to calculate the bookmaker's margin that are used for professional bettors in search of value bets.

Veselin Ignatov

By Veselin Ignatov

The betting margins are key when deciding which online bookmaker to use. They reveal how much money the given site makes when someone places a bet. Hence, the operators that offer lower margins usually provide punters with better odds.

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What are Betting Margins?

Betting margins are the differences between the actual probability of a given outcome and the odds that the given bookmaker offers. In other words, this is similar to a “fee” that the given operator charges you when you want to place a bet. The idea of those things is to allow the bookmaker to have the edge over punters, no matter the outcome.

Unsurprisingly, people need to know more about the betting margin before choosing a given iGaming operator. This information will allow them to select a more suitable operator and have access to better odds.

How to Calculate Betting Margins

To calculate betting margins, players must follow a couple of steps, depending on the market. Although they are easy, inexperienced punters may have difficulties, so we’ve listed them below.

Margin Calculation on a Two-Way Market

Learning more about the margin in betting requires you to use a specific formula. For the Two-Way options, which are popular among sports like cricket and tennis, you have to use the following calculations:

(1/the odds in decimal) x 100 + (1/the odds in decimal) x 100 = Betting Margin

Here is an example of a fictional tennis match between Rafael Nadal (1.5) and Nick Kyrgious (2.3). Using the formula above, we do the following:

(1/1.5)*100 + (1/2.3)*100 = 66.6 + 43.4 = 110 = 10% betting margin

Margin Calculation on a Three-Way Market

Learning more about the betting margin in a three-way market requires you to use a similar formula to the one mentioned above. However, you also have to add the possibility of a draw to the equation, so here is how it works:

(1/the odds for home) x 100 + (1/odds for draw) x 100 + (1/odds for away) x 100 = Betting margin

Although people can use the three-way betting markets on multiple sports, football is the most popular one. So, here is an example of a random event between Real Madrid and Barcelona (2.2 home), (3.5 X), (2.8 away):

(1/2.2) x 100 + (1/3.5) x 100 + (1/2.8) x 100 = 45.4 + 28.5 + 35.7 = 109.6 = 9.6% margin in betting.

Margins and Exchange Commissions

Although many punters use standard betting options, some players are more interested in betting exchanges. Unsurprisingly, those places use a slightly different formula because they also have to add their commission. As a result, you have to use the following equation:

1 + ((1 – (the commission/100)) x (the odds – 1)) = you get the exchange odds, assuming you are aware of the commission

Once you learn about the odds, you have to use one of the formulas mentioned above, depending on the event. For example, let’s say you use an exchange to punt on a tennis match between Grigor Dimitrov (4.2) and Stefanos Tsitsipas (1.3), and the exchange’s commission is 2%:

1 + ((1 – (2/100)) * (4.2 – 1)) = 4.14 for Dimitrov

1 + ((1 – (2/100)) * (1.3 – 1)) = 1.29 for Tsitsipas

Now that we know this info, we use the following:

(1/4.14) * 100 + (1/1.29) * 100 = 24.15 + 77.52 = 101.67 = 1.67% margin

Using a Betting Margin Calculator

If you want to know more about the margins before you start betting but don’t want to use any formulas, there is another solution. Nowadays, you can access a margin calculator that will do all the maths for you. Add the needed values and check your margins in seconds.

What is a Margin Bet?

A margin bet is when you wager on the correct winner in a given match and the winning margin. The bookmaker determines the latter because it breaks the number of different outcomes by creating a points margin.

Usually, people have access to two types of margins:

  • Broad points rage
  • Narrow points range

For example, let’s say you want to bet on a basketball match between the Philadelphia 76ers and Boston Celtics. The latter is the favourite, which is why bookies allow users to place a margin bet by choosing several other variations, depending on the potential points difference.

You can bet that Boston Celtics will win by having a 3-6 points advantage, a 7-9 points lead, and more. Some bookies even allow you to wager on a 20+ margin, which means there will be at least a 20+ points difference between the two teams. Unsurprisingly, this affects the odds.


What is a Fair Market?

A fair market is when the bookmaker offers lower margins so that players can win more if they predict their bets.

What is Considered a High Margin?

Usually, some people consider 20% to be a high margin, but this is not true for everyone. Some bettors think that 10% is also a high margin.

What is a Tri Bet?

Tri Bet is a specific market that allows you to wager on three options. Depending on the event, you can find things like “Team 1” to win by 20 points, “Team 2” to win by 20 points, and “either side to win by 19 points or less than that”.


Veselin Ignatov

Veselin Ignatov

Veselin's primary job is to create unique content, such as reviews and analyses of different bookmakers and other topics from the iGaming industry.