Betting odds can be intimidating for beginners, but they show both the probability of an outcome and how much you stand to win. However, betting odds can come in many forms, such as decimal, fractional, and American odds when using World Cup betting sites. If you are a novice bettor looking to improve your understanding, The Standard has broken down the detail and has you covered. We also have plenty of World Cup guides if you are planning to bet on the World Cup for the first time this summer.
What are betting odds?
Betting odds are how betting sites represent the probability of an outcome. Lower odds mean an outcome is more likely but a smaller payout, whilst higher odds indicate an outcome less likely to happen but a bigger payout. UK bookmakers traditionally use fractional odds, but most will let you switch to decimal via their settings. For example, using England's World Cup odds of 13/20 to beat Croatia in their first 2026 World Cup group stage game. This indicates England are the favourites, whilst Croatia's price at 7/2 reflects they are the underdogs.
How fractional odds work
So how do you read fractional odds? The number on the right is what you stake to win the number on the left. So 3/1 odds return £3 profit on a £1 stake. If the bet wins you are paid out the winnings, whilst receiving your initial stake for a total of £4. If you prefer to work in percentages to weigh up probability, there is a maths shortcut: Take the right-hand number, divide it by the two numbers added together, then multiply by 100. Using the same 3/1 odds, it would be 1 divided by 4 multiplied by 100, giving 25 per cent. The price of Spain winning the 2026 World Cup outright at 5/1 implies roughly a 16 per cent probability of Spain winning the tournament.
Favourites, underdogs and odds-on
The favourites are the side with the shortest odds, and thus, more likely winners. On the flip side, the side with the longer odds are described as underdogs. Odds-on is a term used where the number on the left is smaller than the number on the right - for example, 5/6 or 1/2. To win £1 on these bets you have to stake more than £1, as the bookmakers rate the outcome as more likely than not. 1/1 odds - called evens - imply an equal probability of an outcome happening or not. So for the first game of the 2026 World Cup, Mexico's odds are 2/5 to beat South Africa. Thus, Mexico are odds on to win. South Africa's chances of 7/1 imply they are a credible underdog. The World Cup provides plenty of welcome offers giving free bets, but bear in mind that some UK bookmakers won't accept odds-on selections on free bets or promotional World Cup offers.
How decimal odds work
Decimal odds are a single number that represents the total return - including the initial stake - per £1 staked. Simply multiply your stake by the decimal to get a total return - for example, odds of 5.00 with a £1 stake would equal £5 return, with a £4 profit. To turn decimal odds into a probability just divide 100 by the decimal. So, 5.00 is 100 divided by 5 equals 20 per cent. The practical difference with fractional odds is that decimal odds includes the stake in the number, whilst fractional odds shows profit only. The same price in two formats would look like 4/1 and 5.00.
American odds explained
American odds, sometimes called moneyline, use a + or - sign. These odds are most common on NFL, NBA and NHL markets. Positive numbers (+) show profit on a £100 stake. So, +250 returns £250 profit on a £100 stake. Negative numbers (-) show the stake required to win £100. Odds of -170 means you must stake £170 to win £100. A good rule of thumb is that + always shows the underdog, whilst - always applies to the favourite.
What are in-play odds?
In-play odds are live prices offered once an event has started. These are available on most major sports but not on horse racing, as the events are too short. Prices move with what is happening during the game, meaning odds can quickly change. A goal shortens the scoring side's price and lengthens the odds of the opponent. So, if England lead 1-0 at half-time in a World Cup, England's match-result price will drop sharply from the pre-match number.
Betting odds - frequently asked questions
What does odds-on mean?
Odds-on refers to a price where the smaller number sits on the left of the fraction (e.g. 5/6). The bookmaker rates the outcome as more likely than not, so the bettor has to stake more than they would win in profit.
What do + and - odds mean?
The symbols + and - are hallmarks of American odds, or the moneyline. The + signals an underdog, with the figure showing profit on a £100 stake (e.g +250 returns £250 profit). Meanwhile, - indicates the favourite, with the figure showing the stake required to win £100 (-170 means staking £170 to win £100).
We aim to offer every online gambler and reader of The Standard a safe and fair platform through unbiased reviews and offers from the UK's best online gambling companies. Gambling can be addictive, always play responsibly and only bet what you can afford to lose. Gambling sites have a number of tools to assist you to stay in control, including deposit limits and time outs. If you think you have a problem, advice and support is available for you now from BeGambleAware or Gamcare. Any offers or odds listed in this article are correct at the time of publication but are subject to change. Terms & Conditions apply to all offers.
