Sports betting odds are designed to, at a glance, give readers an idea of how likely it is that each team/competitor will win as well as how much money you could make with a successful bet on that outcome. In other words, you can use them to get a quick idea of the underdog and the favorite.

To decide what odds they offer, bookmakers look at a range of factors. This might include everything from what other sportsbooks are offering through to the results of previous matchups. They’ll adjust those odds in real time, based on factors like injuries and the weather, as well as the amount of money staked by bettors on each outcome.

The fractional odds are considered to be the most commonly used form of odds form of odds presentation by bookmakers in the UK betting market. They are also referred to as “British odds” or “traditional odds”. The presentation of these odds shows how much the bettor will win from their bet compared to the amount they bet.

As an example, as shown in the images below, you're placing a bet on the favorite for the horse race as shown in the images below. The favorite is Acolyte, at odds of 5/2. The fractional odds show that if you placed a bet of $20 then you would win a net profit of $50*. Your stake is returned to you on a winning bet, so the $50 is your actual profit on the bet.

The advantage of fractional odds is that it is flexible and shows that if you bet $40 then at odds of 5/2 you would win two and a half (5/2 = 2.5/1) times that amount so you would win $100. It allows you to work out your winnings based on your bet.

You bet $20 at odds of 5/2. $20/2 = $10 and $10x5 = $50 profit, if the bet is a winning one.

If you'd placed a bet of $20 at odds of 2/5 instead. $20/5 = $4 and $4x2 = $8 profit, if the bet is a winning one.

On any winning bet, your stake is also returned to you.

Example of fractional odds

Those bettors that are unfamiliar with fractional odds might find it difficult working out their percentage chance of success. It is possible to estimate your probability of success based on the odds. However, it should be noted that odds can fluctuate in the run-up to, and even during, a sporting event so the odds only represent an estimate of the probability of success at that time. These odds, and the implied probability of success, can change before or after the bet has been placed.

The American odds are, unsurprisingly, most popular within the US market. These odds work very differently to fractional odds in the fact that they operate separately for favorites and underdogs. They are also referred to as “moneyline odds”.

Example of American odds

The way that American odds work for betting on a favorite is that it shows how much money you would have to risk in order to win a certain amount. Imagine for example you were betting on the Campeonato Brasileiro Serie B soccer match between Boa Esporte Clube and Salgueiro AC, as shown in the images. You would need to bet $138 on a Boa Esporte Clube win at odds of -138 in order to win $100. This is due to Boa Esporte Clube being the firm favorites to win the game.

On the flip side, when it comes to the underdog, the odds are represented in a different manner. Instead, they show how much you would win if you bet the $100. So, using the same example in the images, if you decided to bet on Salgueiro AC in that match at odds of +118, then you would win $118 if you bet $100. This means a total return of $218 (with your original $100 included).

The use of decimal odds is something that has become more prevalent during recent years. They are most widely used in mainland Europe and by Australian bettors, but younger bettors are beginning to favor them more and more with the ever-growing popularity of sports betting online.

Example of decimal odds

Decimal odds are presented to show the bettor how much they will win without stating what bet is required. In our image example above, the contenders for the Copa America football tournament can be seen listed. If you were to place a winning $100 bet on the favorites Argentina at the price of 2.38 then you can expect to win $238, inclusive of your original $100 stake. This is because $100 x 2.38 = $238. This equates to a net profit of $138 to a stake at risk of $100.

The presentation of these odds might appear to be daunting upon first glance but it’s soon clear to see that they offer an immediate insight into your potential winnings, inclusive of the stake. As a result, they are very popular with online sports betting sites and bettors alike. If you’re used to fractional odds but wish to give decimal odds a go, take a look at our conversion chart below. Note that the net winnings to a unit stake is one less than the decimal odds. For example, a $100 stake at decimal odds of 2.38 wins $238 inclusive of the $100 stake if the bet is successful. In other words, you're making a net profit of $138 for the $100 risked.

Mobile sites or dedicated apps are by far the most efficient way to keep track of up-to-the-minute odds as the sporting action unfolds. You’ll be able to place your bets immediately before and, thanks to in-play betting, during an event no matter where you are, subject to the laws which apply to whatever jurisdiction you happen to be in when placing your bet.

Apps can be particularly useful for this, as most will update their odds automatically (and in real time). Many also send you notifications of the latest updates, so you can choose the perfect time to strike.

Choosing which format of odds to display when sports betting is mostly down to a matter of personal preference. This will usually, but not always, be the type of odds most associated with where you live.

We should point out that the majority of sports betting sites offer the option to choose which type of odds you want to view when you’re looking at placing a wager. There are also odds calculators out there that can help you convert between different types of odds.

The bottom line is that it doesn’t really matter which type of odds you opt to use: you won’t win or lose more cash by choosing a certain way of viewing odds. It therefore makes the most sense to choose the one you’re most at ease with and use that whenever possible.

• 1

  Don’t be afraid to shop around

  Some sportsbooks will update their odds based on circumstantial changes more quickly than others. Armed with the knowledge of how to calculate potential winnings, you can see what represents the most profitable bet for you, should you end up winning.

• 2

  Assess the risk

  Use what you know about odds to figure out what you view as an acceptable level of risk when betting on an underdog. $1 wagered on 20/1 odds, for example, relatively low risk bet in terms of maximum downside. Most bettors would, however, feel uncomfortable betting $100 on 100/1 odds (despite the huge potential profit) because the odds are stacked so heavily against you.

• 3

  Check back regularly

  It’s important to keep an eye on the odds, ideally using a smartphone or tablet if you’re on the move. If you see odds shifting quickly in one direction then it’s very likely something has changed (e.g. weather, location or a key injury). That may influence who you back in the contest, or at least how much you wager.

• 4

  Stay in the know

  Make sure to take advantage of insider knowledge. British bookies, for example, may just possibly not be up to speed with what’s going on in upcoming NFL fixtures compared to a superfan who follows breaking news accounts on Twitter will. This is why it can be helpful to wager on a sport you’re a genuine fan of, or at least do your research before placing your bet.