How Are Bookmaker Odds Calculated – 2024 Guide

Anyone who has recently gotten into gambling or betting wants to know about the betting odds or the bookmaker odds. Both the new and experienced players need to know how it is calculated in order to better prepare themselves for any game they will choose to play.

It becomes important to understand how the entire calculation works to find the value you stand to win by playing one hand of any given game. In this article, we will be telling you about how to calculate along with all the terminology you should learn.

Betting Odd Calculation


You need to have some preliminary introduction to mathematics before starting on with the calculation of bookmaker odds. The key mathematical concept which comes into play for the calculation of betting odds is probability. Now, probability is more than the 50-50chance of winning if you flip a coin. It has its own complicated formulae that needs to be learnt and applied in the right manner.

You will be right by saying that gambling, in general, deals with chance. But it is also guess work so choosing one outcome and placing money on it will make you probable to win only if that outcome comes out to be the winner. For instance, you rolled a dice. If you place money on one of 6 outcomes, your probability of winning is ⅙. This roughly translates to a 17% chance of winning.

Through this example, you saw how simple probability can be calculated into a percentage to find the right odds for any betting game. The probability in fraction is called fractional odds and displays very clearly how likely an outcome is supposed to happen. The denominator of the fraction shows the total number of possible outcomes.

The numerator shows how many outcomes one has bet on. For a 1/10 fractional odd, you can say that there is only a 10% chance of the event happening which reduces the chances of winning by 90%. However, fractional odds are written somewhat differently. So, the calculation can be complicated for someone who does not know how to do it.

There can be a fractional number of 1/1 which does not translate to a hundred percent chance of winning. It simply means that the number in the numerator needs to be added to the number in the denominator. Only after this edition can that denominator represent the total number of outcomes. Know more with experts at 20Bet application.

So 9/1 is basically calculated as 1/10 when we try to find out its probability. Similarly, ¼ is actually ⅘ which means that there is an 80% chance of the event happening. The calculation is somewhat inverse so one needs to be very careful while the calculation happens. It is inverse to 4/1 which means ⅕ and give the player at 20% chance of winning on their bet.

How to Calculate Winnings?


After you are done with the calculation through fractional odds, it becomes easier to understand how much one would win with each right bet. Let us take 4/1 as an example. So if you are batting the denominator on winning you will get the amount signifying the four on the numerator as well as the return on the original bet. This means that if you are betting 10 USD on the fraction of 4/1, the total calculation of winnings will be 40 USD.

A very simple manner of calculating the winnings is by multiplying the numerator with the money associated with a single bet. Consider the following for one $10 bet.

  • Win $90 for the odds of 9/1.
  • Get $10 for the odds of ¼.
  • 1/1 will get just as much as you have bet.

Understand the Terms


When you step into the world of gambling there is a lot of jargon thrown around that may confuse you initially. This simply means that certain terms should be understood before starting with the calculations or batting on any game. Here are some common terms:

  • Probability: There may be very few people who have not heard of probability. But specifically with gambling probability means the chances of winning for any individual or team playing any given game. We have already learnt about how probability is used to calculate betting odds. The calculation formula must be the same but the application somewhat different depending on a particular fractional odd.
  • Underdogs: The bookmaker’s odds are very different for the underdogs that attract beginners to make hasty bets. Underdogs are the outcomes that are less likely to occur which means that the price on them in case of a win is significantly higher. In sports betting, an underdog is a team or an individual which has been inconsistent with the performance and is more likely to lose. Might be exciting to put your money on an underdog but there are more chances of losing in such a case then hitting a jackpot.
  • Favorites: These are the complete opposite of underdogs because of their favorability and consistent performance. People can go on these individuals or teams because they have a higher likelihood of winning. Any player who is familiar with betting odds and related calculations can make the deduction on which team is the favorite for a particular game. The main drawback of betting on favorites is that the fractional odds are lower so the winning margin will be less.

The Takeaway

Be open to learning about betting odds before you start gambing. If playing for fun, one does not need to worry about winning and losing because only the thrill matters. But for any experienced player or a beginner who is going into gambling to win, calculating betting odds and calculating them right is of utmost importance. One needs to be very careful while understanding the probability to calculate better in their head even without a calculator. Any sports match can be better enjoyed with the right chances.

About Marija Jovanovic

Hey! My name is Marija Jovanovic, and I work as a content editor and writer at When I'm not working, you'll catch me gaming, designing pictures or travelling. I've got a knack for programming and solving PC troubles, which fits perfectly with my gaming vibe. Off-duty, I mostly spend my time gaming, coding something cool, or travelling to exotic destinations!

Check Also

How Has U.S. Gambling Culture Evolved Over the Years?

As you may already know, US gambling culture has changed significantly over the years. What …

Sahifa Theme License is not validated, Go to the theme options page to validate the license, You need a single license for each domain name.