Sports betting odds explained
Understand the odds in sports betting with our guide

Sports betting is one of the most popular areas of gambling, with many favorites such as NFL, horse racing and football attracting millions of bettors around the world.
How do sports betting odds work?
Fractional odds

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
Dog racing favorites | Ratings | Odds |
---|---|---|
Acolyte (IRE) | 93 | 5/2 |
Mullionheir | 95 | 11/4 |
Lightning Charlie | 95 | 5/1 |
Upstaging | 96 | 5/1 |

Implied probability | Fractional odds |
---|---|
99.01% | 1/100 |
80.00% | 1/4 |
75.00% | 1/3 |
66.67% | 1/2 |
55.56% | 4/5 |
50.00% | 1/1 |
45.45% | 6/5 |
40.00% | 3/2 |
33.33% | 2/1 |
13.33% | 13/2 |
5.00% | 19/1 |
American odds
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


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).
Decimal odds
Example of decimal odds


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.
Decimal to fractional odds conversion chart
Fraction | Decimal | Fraction | Decimal | Fraction | Decimal |
---|---|---|---|---|---|
1/10 | 1.10 | 1/1 | 2.00 | 5/1 | 6.00 |
1/9 | 1.11 | 11/10 | 2.10 | 11/2 | 6.50 |
1/8 | 1.12 | 6/5 | 2.20 | 6/1 | 7.00 |
1/7 | 1.14 | 5/4 | 2.25 | 13/2 | 7.50 |
1/6 | 1.17 | 11/8 | 2.38 | 7/1 | 8.00 |
1/5 | 1.20 | 6/4 | 2.50 | 15/2 | 8.50 |
2/9 | 1.22 | 13/8 | 2.63 | 8/1 | 9.00 |
1/4 | 1.25 | 7/4 | 2.75 | 17/2 | 9.50 |
2/7 | 1.29 | 9/5 | 2.80 | 9/1 | 10.00 |
3/10 | 1.30 | 15/8 | 2.86 | 10/1 | 11.00 |
1/3 | 1.33 | 2/1 | 3.00 | 11/1 | 12.00 |
4/11 | 1.36 | 85/40 | 3.12 | 12/1 | 13.00 |
2/5 | 1.40 | 11/5 | 3.20 | 14/1 | 15.00 |
4/9 | 1.44 | 9/4 | 3.25 | 15/1 | 16.00 |
1/2 | 1.50 | 12/5 | 3.40 | 16/1 | 17.00 |
Betting on your smartphone
Which odds to choose?

Quick tips for placing your bet
Now that you know more about calculating odds, and the different ways they might be displayed, you can use that information to your advantage when placing your next bet. Below, you’ll find a few of our top tips for applying your newfound knowledge to the next bet you place!- 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.