Betting Odds Explained

betting odds explained
Dan A.
by Dan Afteni
Bet Guide

What does 4/1 odds mean? What do odds of 8/13 mean? What are fractional and decimal odds? What is 1/2 odds in decimals? If you’ve ever bet on football or even just looked at a football betting market, you will have seen numbers like this. You may know roughly what they represent, or you may be a complete newcomer to the world of betting odds, but understanding what the numbers stand for is essential to making a success of your football betting.

Difference between odds and probability

The first thing you need to know is that these numbers represent both odds and probability and football punters use them in two ways. For example, let’s say you are considering a bet on Chelsea to win a match at 4/7 odds. The numbers tell you both what your return will be in the event that Chelsea win and what probability the bookmaker has given to a Chelsea win.

In this case, 4/7 represents a 63.64 percent chance. This can also be written as a probability, in which case it would be 0.64. Instead of looking at the odds to work out how much they could win, experienced football punters translate the odds into probabilities before deciding whether to bet. In this case, if you think Chelsea have a better than 63.64 percent chance of winning, you may choose to make a bet. Understanding that odds can also be probabilities is a crucial part of your education as a football punter.

Fractional and Decimal betting odds explained

The odds above were written in the traditional ‘fractional’ style which is particularly popular in Britain, but around the world, decimal odds are becoming increasingly popular. Sometimes known as ‘European’ odds, decimal odds are simple to grasp and most good online bookmakers such as Jetbull will offer decimal odds displays for convenience.

Decimal odds include both your stake and your return. For example, let’s say you want to bet on Manchester United at 1/1 odds. Using the decimal system of odds, this would be 2.0. If you bet £10 at those odds, you can calculate your return by multiplying your stake by 2.0, which in this case would be £20, made up of your original stake and £10 profit.

So the main difference between fractional and decimal odds is that fractional odds are used to calculate your profit, while decimal odds show you your total return. When betting with decimal odds you should, therefore, remove your stake from your return to find your profit.

How to convert decimal odds to fractional?

Some football punters prefer to use fractional odds because they are more familiar with that format or because they want to be able to quickly calculate their profit without having to deduct their stake. Converting decimal odds to the fractional format is relatively easy, though there is a little basic mathematics involved. The process works like this:

  • Deduct 1 from the decimal odds
  • Turn the remaining number into a fraction
  • Reduce the fraction to its simplest form

So if you wanted to change decimal odds of 1.80 into fractional odds, here is how to do it:

  • 1.80 – 1 = 0.8
  • 0.8 = 8/10
  • 8/10 = 4/5

Sometimes this method will produce fractions such as 47/20, which are not normally used in the betting world, so an alternative approach to converting decimal odds to fractional odds is to use one of the many handy online calculators which make the process even quicker.

Fractional to decimal odds

On occasion, you may want to make the opposite conversion. Let’s say you want to express 9/2 odds, 4/1 odds or 1/5 odds in decimal format. How should you go about it? Most top bookmakers such as Jetbull will have a feature that enables you to do this at the click of a mouse, but it is also useful to be able to convert from fractional to decimal yourself, as it helps you to become more comfortable with using odds.

The conversion process is relatively straightforward. Let’s say you want to convert 4/9 odds into the decimal format. All you need to do is turn the fractional odds into a percentage, and then divide the result into 100. Here’s how it works:

  • Start with odds of 4/9
  • Divide the second number into the total of the two numbers: 9/(9+4) = 0.69
  • Turn the result into a percentage: 0.69 x 100 = 69%
  • Divide this figure into 100: 100/69 = 1.45

Use betting odds to calculate winnings

If you’ve struck a winning football bet, you want to be able to quickly calculate how much you have won. This is simple to do, but the method is different, depending on whether you are using fractional odds or decimal odds.

If you have bet £10 on West Bromwich Albion to win against Barcelona at 10/1 odds and the Baggies pull off a shock win, you can calculate your winnings easily:

  • Stake = £10
  • Odds = 10/1
  • Winnings = Stake x Odds: £10 x 10 = £100

This figure represents only your winnings and does not include your stake. So if you had made this bet online with Jetbull, you would find that £110 would be credited to your account, made up of your £10 stake and your £100 winnings.

The same bet would be quoted at 11.0 if it was expressed in decimal odds, and there is an extra step involved in the process of working out your profit;

  • Stake = £10
  • Odds = 11.0
  • Return = Stake x Odds: £10 x 11 = £110
  • Winnings = Return – Stake: £110 – £10 = £100

Being able to calculate your profit and your return from a bet, using both fractional and decimal odds is another skill that will increase your betting confidence.

Record and analyse your bets

One of the most important things you can do to improve your football betting is to record your bets. Many football punters, particularly small stakes or casual punters, don’t bother with this simple step, but an ongoing record of your betting activity, complete with the odds that you obtained for each bet can be a powerful resource to draw on.

By studying the odds of your bets, you may be able to find that you can spot patterns. For instance, you may discover that you are particularly successful with odds-on bets or that you do well with bets at odds of 3.0 or higher. This can help you to get a clearer picture of your betting performance, strengths and weaknesses.

Odds can also be a powerful tool when converted into probabilities. Successful football punters profit by making value bets in which the odds on offer are bigger than they should be, and by checking your records, you can see whether you are finding value.

For example, 9/1 odds equates to a probability of 10 percent. Bets at 9/1 are therefore expected to win around 10 percent of the time. But if you find that your 9/1 bets are winning less often, it may be a good idea to reconsider your strategy. On the other hand, if your 9/1 bets are winning more than 10 percent of the time, you know you’re on the right track.

How to change to decimal/fractional odds on our website?

Among the many handy features on the Jetbull is our odds conversion facility, which makes it easy for punters to switch between fractional and decimal odds.

If you’re using Jetbull on your desktop machine, simply click on the Sports Betting option then head to the Help and Support section on the right-hand side of the page. Next to the date and time display, you will find a drop-down menu that will enable you to switch between fractional (UK) odds and decimal (EUR) odds, as well as US odds.

Punters using Jetbull on their mobile can click on the person silhouette at the top of the page next to the deposit icon.

This will bring up your account page and by clicking on Settings, you will open a new page on which you will be able to switch between the different odds formats via a drop-down menu, making it easy to choose your preferred odds on Jetbull.


It is impossible to be a successful football punter without becoming familiar with sports odds and how they work. Odds can tell you about the probability of a bet being successful and about how much you stand to win, and knowing how to use odds, both fractional and decimal, will enable to make better wagers and to fine-tune your online sports betting experience.