Sports Betting Odds

Betting OddsBetting on sports is extremely popular in the UK and its popularity continues to grow each year. Despite this, many UK punters are often left asking ‘how do betting odds work?’

Here are at MansionBet, we’ve put together a comprehensive and informative guide to using betting odds to calculate the probability of a particular outcome and crucially, how to know if you’re getting value from your bet.

We’ll also explain the different odds formats and outline the various ways to calculate your potential returns.

UK bookmakers will set odds on every single sporting event. This may also be known more informally as the ‘price’ on a particular team or player to triumph. Odds are arguably the most crucial element of having a flutter as they inform punters of the amount they can expect to receive should they successfully back a winning selection.

Experienced and successful punters use these odds to calculate whether they are getting good value from their wager. Odds are a reflection of how the bookmaker views an event, however, if you conduct your research or have in-depth knowledge of a particular player or team, you may believe that these prices are incorrect and this is when many savvy and experienced punters look to take advantage of the prices.

Odds may be displayed in one of three different formats: Fractional, Decimal or America. Many online sportsbooks Boylesports or Bet UK allow you change the format upon signing up for an account.  

Basic Betting Odds 

You’ve probably heard of an ‘Odds On shot’ or perhaps a bet being ‘Odds Against’. An Odds On price is where the potential winnings are lower than the amount that you stake. Don’t worry, this isn’t some sort of scam, as your stake will also be returned. In order to win big, you will often have to risk a larger amount.

If displayed as a fraction, Odds On bets show the smaller number on the left with the larger number on the right. For example – 7/10.

In this example, you would have to wager £10 in order to win £7 (plus your £10 stake).

If displayed as a decimal, it will begin with a 1. For example – 1.83. In this example, you will win 83p for every £1 that you wager on this bet (plus your stake).

Odds Against bets tend to be more popular with punters hoping to receive far bigger returns for their outlay. In this instance, your returns will be greater than the amount staked.

If displayed as a fraction, an Odds Against bet will have the larger number on the left. For example 2/1. Here, you would receive £2 for every £1 (plus your stake).

If displayed as a decimal, the odds will begin with the number two or above. For example 2.5. Here you’ll receive £2.50 for every £1 staked (plus your stake).

It is worth noting that odds of 2.00 or 1/1 are neither Odds On nor Odds Against. This price will double your money. If you placed a £10 bet at these odds, you would win £10 (plus your stake). In the UK, it is often referred to as ‘Even money’ or ‘Evens’.  

Odds Format

As outlined in our betting odds explained section, odds can be displayed in many different formats. In the UK, sports betting sites tend to favour fractional odds, however, betting exchanges prefer to use decimal. Decimal odds are widely used throughout Europe, so if you sign up for a European sportsbook, they may opt for this format.

The third format is American. This tends to be exclusively used by US bookmakers, however, some UK operators do offer punters the chance to use them.

  • Examples of Fractional Odds – 8/11, 2/1, 6/4, 7/2, 9/1
  • Examples of Decimal Odds – 1.72, 3.00, 2.50, 3.50, 10.00
  • Examples of American Odds - -137.5, +200, +150, +350, +900

American Odds can be trickier to understand. They are written in a format which tells you how much you would need to wager in order to win $100. For example, with odds of -150, you would be required to stake $150 in order to make $100 (you would also get your stake back). Anything with a + is odds against and anything with a – is odds on.

If you wish to change the odds format, this option tends to be located in account settings. Occasionally it can be found at the bottom of the home page.  

Top Bookmakers with Best Betting Odds


Prior to any sporting event, UK bookmakers and betting sites will price up the probability of each potential outcome. This is often referred to as ‘creating a book’.

For example in a Champions League football match, they may decide that there is 70% chance of Manchester City beating Benfica. This is how they have calculated the probability:

Man City – 70%  
Draw – 21% 
Benfica – 9%

Total = 100% 
As a result, they are likely to be priced up at around 7/10. However, in order to gain a regular profit and ensure that they don’t make a consistent loss, the bookmakers will alter the prices to include a built-In profit. This involves adding a percentage of around 5-10%.

If they fear that a particular team or player is proving too popular, they may alter the prices to avoid substantial loss. In this example, if lots of money was coming in for Manchester City, they may opt to reduce the price to around 6/10 in order to potentially deter punters from excessively wagering on the Premier League side. Bets at this price will also pay out significantly less than 7/10.

If you placed a £200 at 7/10, you will receive £140 profit (plus your stake) whereas at 6/10, you will receive just £120 (plus your stake).  

In some cases, a bookmaker may not be able to separate two players or two teams and as a result, they may be exactly the same odds.  

Once you’ve got to grips with betting odds, they soon become relatively simple to understand. They reflect the chance of a particular outcome. Anything which is Odds On has more than a 50% chance of occurring.

The higher the betting odds, the less likely an outcome (according to the bookmaker). This is where experienced and successful punters aim to outsmart bookmakers and prove that their prices are incorrect.  

In order to successfully use betting odds, you must always ask the question – ‘is that good value?’

If the answer to this question is positive, then it may be time to place a bet. In terms of assembling multiple bets such as an accumulator, this is far less important, however, it’s still best to avoid incredibly short odds on prices such as 1/5 and 1/9 as these are unlikely to make much difference to your potential returns.  

Betting odds calculators are widely available and these are able to quickly calculate your returns, however, it is also incredibly straightforward to work it out yourself. The majority of betting sites in the UK will automatically calculate your returns if you are a fan of betting on multiples.  

Fractional Odds  

If you place a bet at 9/4, you will receive £9 for every £4 that you stake. However, if you wish to wager either more or less than £4, it isn’t always this simple. In order to work this out, it is best to work to a £1 stake.

Calculating potential returns:  

9 divided by 4 = 2.25  
Multiple 2.25 by your stake.  
For example - £50 x 2.25 = £112.50 (+ your £50 stake).  
You will receive £162.50 if you bet is a winner.

Decimal Odds

It is relatively straightforward to calculate your returns using decimal odds. You simply multiply your stake by the odds. If you wish to calculate your profit ONLY, then it is important to remember that you must subtract 1 (your stake) from the total. However, if you wish to calculate your total returns, then there is no need to do this.  

If you place a bet at 2.75, you will receive £2.75 for every £1 staked (including your stake)

Calculating potential returns:  

£10 x 2.75 = £27.50  

This includes the £10 stake. You have made £17.50 profit on this bet.

American Odds

Although American Odds are far less frequent in the UK, it is still important to understand how to calculate your returns in this format.

Money Line odds are calculated to winning $100. So at odds of +125, you know that for every $100 staked, you would receive $125.

Calculating potential returns:  

Odds of +150. You would need to wager $100 in order to receive $150.  
Odds of -150. You would need to wager £150 in order to receive $100.

In order to calculate your returns for positive values, you need to use this sum:  
Stake x (Odds divided by 100)  
$50 x (+125 /100) = $62.50

In order to calculate your returns for negative values, you need to use this sum:  
Stake divided by (Odds divided by 100)  
$50 / (+125 /100) = $40 (plus your stake) 

When it comes to placing a bet, finding value is absolutely essential. For the majority of punters, it may take a long time to become an expert in this sphere. It is important to remember that successful punters do not simply find value in the very first market that they come across.

Thankfully, betting sites such as 10Bet and Betzone have hundreds of different betting markets priced up on a daily basis, so it’s always important to shop around for value and ensure that you compare each bookmaker’s odds.

Each match will have its own betting markets with odds available on each outcome. These odds may not just be restricted to the winner market, with other options such as goals, tries, points, players also priced up by the bookmakers.

For example, in a tennis match, the bookies will price up each player to win the match, the total number of games, the total number of sets and a handicap market for each player (giving each player a specific handicap / disadvantage).

When it comes to football betting markets, the bookies will price up each team to win, the total number of goals, specific players to score and a correct score market.

Successful punters are able to search through the various markets in order to find the best value.

Horse Racing Betting Markets  

Horse Racing bettingWhen it comes to horse racing markets, the bookies price up each horses’ chance of winning the contest. You can also back a horse each-way and these bets will pay out at either 1/4 or 1/5 odds if your chosen horse finishes in the top two or three (depending on the number of runners).

Although some races may have an odds on favourite, the majority of contests tend to have a number of bigger prices (example 8/1 or 10/1). Surprises regularly occur in horse racing so the chances of landing some big price winners are increased.

Football Betting Markets  

Football betting sitesFootball remains the most popular sport in the UK and as a result, betting on football markets is a regular pastime for many punters. Although the 90 minute (1x2) markets remain the most popular option, there are several other markets such as Under/Over 2.5 Goals and First Goalscorer which are often favoured when it comes to finding value. Bet Builders allow punters to create their own bets using a variety of markets and these have become increasingly popular in recent years.

Odds on football betting markets can be a little prohibitive, hence the reason that many UK punters enjoy placing football accumulators each weekend.

Golf Betting Markets  

Golf BettingThroughout the season, various golf tournaments take place each weekend. As a result, the bookmakers have a constant stream of golf betting odds and markets available. The most popular way of wagering on golf is the tournament winner market and it is possible to find generous odds on players to finish in the top 5/10/20.  

There are numerous other markets available including ‘First Round Leader’, ‘To Make the Cut’ which offer alternative options.