What Does Overround Mean in Betting?

Discover the meaning of 'overround betting' and explore its significance in the world of sports betting. Uncover examples of optimal bookmakers offering favorable overrounds and diverse betting opportunities.

Odds boards in a Las Vegas sportsbook
Alyx Tzamantanis.

Written by: Alyx Tzamantanis

(Sports Betting Editor )

Fact checked by: Naim Rosinski

(Content Manager)

Last updated: 2024-05-09

6 minutes read

Have you ever heard the phrase ‘overround betting’ and wondered what it means?

Today, we’re going to answer the question ‘what does overround in betting mean?’ with some examples of great bookies where you can find good overrounds and other sports betting options. 

Overround Explained 

The term ‘overround’ simply refers to the profit margin added to odds by bookmakers in order for them to make money on a sports event, regardless of the outcome.

For example, in a simple two-outcome event like a coin toss, landing either heads or tails has a 50% chance of occurring. A fair bookmaker would offer odds of 2.00 (or "even money") for each outcome.

However, in reality, a bookmaker might offer odds of 1.91 for each outcome. This implies a probability of approximately 52.4% for heads or tails.  

When you add up the probabilities of both outcomes, it exceeds 100%. This represents the bookmaker's profit margin or overround.

How Important is the Overround in Betting? 

Overrounds are important in sports betting for many reasons. Firstly, a bookmaker that doesn’t make any money won’t stick around for very long! So we wouldn’t have many sites on which to place bets.

Secondly, overround can give you, the punter, some great insights into the bookmaker and its events.

Use overround to assess a sportsbook

Overround provides insight into the fairness of the odds offered by bookmakers. A lower overround indicates that the odds are more favourable to bettors, as there is less built-in profit margin for the bookmaker.

Bettors can use overround calculations to assess the competitiveness of odds and make more informed betting decisions.

Use overround to find value bets 

You can compare overrounds offered by different bookmakers to find the best value. By identifying bookmakers with lower overrounds, you can potentially maximise profits and improve your overall betting experience. 

Get a better understanding of odds with overround 

Overround calculations involve converting odds into implied probabilities. This process helps you understand the likelihood of various outcomes according to the bookmaker's assessment. 

Overround in Different Types of Bets 

Overround exists in various types of sports bets, including traditional fixed-odds betting, spread betting, and others.

Here's how overround works in each type of bet…

Fixed-odds betting

In this type of betting, bookmakers set the odds for each possible outcome of an event, ensuring that the total implied probability exceeds 100%. This excess probability represents the bookmaker's profit margin or overground.

Spread betting

In spread betting, instead of betting on a fixed outcome, bettors wager on whether the actual outcome will be above or below the spread set by the bookmaker.

The spread represents a range of possible outcomes, and you can bet on whether the actual outcome will be higher (buy) or lower (sell) than the spread.

The overround in spread betting is embedded in the difference between the buy and sell prices set by the bookmaker. The wider the spread, the greater the overround.

Overround & Betting Exchanges 

In traditional sports betting, bookmakers set the odds for various outcomes of an event, ensuring that the total implied probability exceeds 100%. This represents their profit margin, known as the ‘overround’.

However, in the context of betting exchanges, the concept of overround works slightly differently, as you don’t have a bookmaker acting as ‘the house’.

Instead, when you bet with an exchange, punters set their own odds and bet against each other in a peer-to-peer marketplace. The overround is influenced by factors such as market liquidity, user behavior, and the exchange's commission structure.

So, while the concept of overround still exists on betting exchanges, it operates differently compared to traditional bookmakers.

Comparing Overround Across Bookmakers 

The best way to compare overrounds is to take an event and collect the odds from different bookmakers.

You can then calculate the overround, either by dividing 1 by the decimal odds to give you the percentage probability, or by using an online overround calculator.

We did some research over a range of events and markets. Let’s take a look at the results! 


This international bookmaker is a firm favourite with betting fans, as it offers a wide range of sports from many different countries.

During our research, Melbet came up with some pretty decent scores. They produce fair overrounds, meaning that the punter is getting fair offers and competitive odds.  


This renowned bookie is another one popular with fans for its wide-reaching sportsbook and wealth of markets.

When looking at betting overrounds, 1xBet score rather well. Its margins are generally fair across its huge sportsbook, with moneyline and parlays giving better odds than prop bets. 


Known for its simple site with a good range of markets, LeoVegas’ offers some great odds on certain events.

While researching overround horse racing, we found LeoVegas to produce a slightly lower overround than some of its competitors. This means that LeoVegas might make less profit from punters than other bookmakers. 


A vibrant and exciting sportsbook, Parimatch offers a huge range of sports, events and markets to wager on.

When it comes to overrounds, Parimatch performs a lot better than some of its rivals, with very fair profit margins, particularly in regards to overround horse racing. 


A world-renowned bookmaker, Betway stands out for its impressive sportsbook and regular promos and offers.

In terms of overrounds, Betway came out on top in our research, providing some of the lowest profit margins, potentially making it one of the fairest bookmakers in the industry. 

Why Does a Bookie Need Overround? 

Quite simply, bookmakers need overrounds as this is where they make their money. Without profit margins, bookies wouldn’t be able to offer such competitive odds.

Not to mention, they couldn’t offer all the perks we’re used to, such as modern websites, apps, live streams and in-play betting via state-of-the-art technology.

Therefore, while we don’t like to think of a bookmaker taking our money whichever way we bet, the fact is that they need profits in order to provide us with the best online betting experiences possible.

For more features, guides, and the latest news in the world of sports betting, make sure you always come to us right here at Sportsboom.com.

Alyx Tzamantanis.

Alyx Tzamantanis

With 10 years of experience in content writing, Alyx has produced countess guides, reviews and articles covering a wide range of topics in the iGaming industry. She loves anything to do with online casinos, as well as UK and international sports betting.

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