Sports Betting

How betting odds work: Sports betting odds explained

Whether you are a novice bettor or just curious how the sports betting odds work, your search for information ends right here. We will teach you how the odds work, explain (with examples, of course) the action the bettors take on those odds, contrast the different types of betting odds, and by the time we are done – you should be able to bet like a pro. Well, kinda; at the very least, one should be able to spot right away the favorite from the underdog and figure out how much you’d get paid if you were to place a winning bet on those odds. But we are getting ahead of ourselves, let’s cut through the fluff and get right into it, first explaining the odds, then working through some examples of the American, decimal and fractional odds. This guide may start a bit dry at first, but stick with it, as we will be working in some fun part later.

[alert variation=”alert-info”]Betting Odds Explained[/alert]

To put it as simple as possible, the odds indicate a probability of an event to happen. You can think of the odds as “what is the chance of something happening?”. Now, some may assume that “odds” and “betting odds” are the same thing, but there is one significant difference: money. The betting odds don’t show how likely something is to happen, per se, only how much you will get paid if that event happens. You can, however, deduce the likelihood if you contrast the betting odds. We know it doesn’t make much sense right now, and we will dive deeper into the actual odds a bit later, but you should know right away that “odds” and “betting odds” are not the same thing.

For example, if you flip a coin, the mathematical odds of getting heads is 50-50, but if you have 2/1 odds on a team to win, it doesn’t mean that there is 50% chance that the team will win: it simply means that the sportsbook will pay you double, if this happens. In the same example, the other team may have 3/2 odds to win. Now when you compare the two, the second team has a better chance of winning (again, according to the sportsbook, not based on any quantitative measures), than the one with 2/1 odds. Mathematically this doesn’t work – you can’t have one team with 50% chance to win and the other with 75%! If you find this a bit hard to grasp – don’t worry, just remember that betting odds are mostly about the payout of a bet, not probability in the same way the simple odds are.

If we contrast the basic concept of odds with the betting odds – the sports betting odds indicate two things:

  1. What is the probability of something related to a sporting event to happen (as compared to other options): Depending on the particular odds, it could be the perceived probability of a football team winning the game, a horse winning a race, or a basketball player making a 3-pointer in the first half. The limit on what the sportsbooks could offer odds is literally their oddsmakers’ imagination (and the risk they are willing to take).
  2. The payout on that bet: The odds not only hint to the chances of something happening, but they also indicate how much the bettor would be paid by the sportsbook if that event actually occurs. This is the most important aspect of the sports betting odds.

We should also note right away, that when it comes to sports betting, there are three types of odds you may see, depending on where you place your bets:

  • Fractional Odds (for example, 3/1)
  • American Odds (for example, +120)
  • Decimal Odds (for example, 2.40)

The fractional and American odds will be seen at US sportsbooks (like those in Las Vegas or offshore sportsbooks), while the decimal odds are most popular in Europe and Asia. As warned earlier, this is on the dry side, and most people learn best by examples, so let’s get to the meat and potatoes. We will look at all three types of odds, and after seeing some examples, we guarantee that you will have no issue understanding how the sports betting odds work.

[alert variation=”alert-info”]Fractional Betting Odds[/alert]

Examples: 2/1, 5/1, 7/2

Even though they are not the most used style of betting odds with the sportsbooks, the fractional odds are the easiest to comprehend and learn, they could be seen all over the world, and the fractional odds are the most popular type, i.e. they are the “household name” of odds. As the name implies, the fractional odds take the form of a fraction, for example, 5/1 (pronounced “five to one”). See also how betting odds work at this guide. These numbers simply indicate how much the sportsbook will pay you if your bet is a winner. One may find these type of odds at a horse race or OTC. For instance, you may see that the odds on a horse to win the race are 3/1. This means that for every $1 you bet – the sportsbook will pay you back $3. In essence, the first number shows you how much you would get paid if you bet the second number. There is nothing really complicated about fractional odds and they are quite easy to calculate in your head, even if you get something like “5/2” odds – you may have guessed already that in this case the sportsbook will pay $5 for every $2 wagered; simple as that. And now you know why we began this guide with an explanation of the fractional style betting odds.

[alert variation=”alert-info”]American Betting Odds[/alert]

Examples: +120, -210, +500

This is where we get to the real deal and where we hope to “earn our keep” – the explanation of the American style betting odds. If you are int he United States, these are the betting odds you will most likely see, whether when placing bets at the Vegas sportsbooks or reading sports articles mentioning betting odds. The name comes from the fact that this style of betting odds would be seen only in the US. At first glance, this type of odds may seem quite intimidating and hard to understand how they work, but with a good explanation and some practice – you’ll be a pro in no time. We will try our best to make this a simple as possible and hopefully you will get it at first read, but if you don’t – just bookmaker this page and refer to it when needed.

American betting odds take the form of a number with either a plus (+) or minus (-) sign in-front of said number. For example, -210 or +180. For this type of odds we will use NFL football as an example for placing bets, so at the beginning, you could think of it this way: “If there is a plus in front of the number, I will get paid more than what I bet”, i.e. the team is the underdog, and “If there is a minus in front of the number I will get paid less than what I bet”, i.e. the team is the favorite. Now that we know this simple trick, let’s see how the American betting odds are calculated.

[table style=”table-bordered”]

If the sign is “+” (plus) It shows how much you will get paid if you were to bet $100 Example: If the odds are +210, it means that for every $100 you bet, the sportsbook will pay you back $210.
If the sign is “-“ (minus) It shows how much you have to bet to make $100 Example: if the odds are -210, you have to bet $210 to make $100 profit


As you can see, calculating American odds is not a simple job, positive odds (with the plus sign) being easier than the negative, but let’s give it a twirl.

Calculating Positive Betting Odds (i.e. +180)

The easiest way to calculate positive betting odds if to simply move the decimal point two spaces to the left (essentially turning the American odds into a form of decimal odds), then multiply the resulting number by your desired wager to get the “win amount” of the bet, then simply add your stake to get the total money you will get back from the sportsbook. For example, let’s say that the Green bay Packers are +150 underdog to win the game. You simply take the 150 number, move the decimal point two position to the left, turning 150 into 1.50, then multiplying by your bet. If you wanted t bet $10 on the Packers winning the game, your math should look like: 1.50 * $10 = $15 in winnings, $15 + $10 (your original stake) = $25 total payout. And if you want to take it a step further with the shortcuts, you can simply calculate your total payout right away, by adding “1” to the odds once you convert them to decimal, i.e. 1.50 + 1 = 2.50 * $10 = $25.

We can already tell that you are feeling cocky about calculating positive betting odds, so let’s try another scenario: the NY Giants are +195 underdog and you want to bet $75, what’s the possible payout? If you have your answer, click on “answer” below to see if you got it right.

[tabs style=”nav-tabs”]
[tab title=”Question”]Odds: +195

Bet Size: $75[/tab]
[tab title=”Answer”]To Win Amount: $146.25

Total Bet Payout: $221.25

Your Math Should Look Like: (1.95 * $75) + $75 = $221.25[/tab]

If you are a math-head you can use the following formula to quickly calculate the total payout of a bet placed on positive betting odds:

[alert variation=”alert-success”][(odds/100)+1] * $ bet = $ total payout[/alert]

Congratulation, now you know how to calculate the positive betting odds, let’s move on to the harder side of the American odds:

Calculating Negative Betting Odds (i.e. -110)

On first look, the negative form of the American betting odds may seem like an adventure waiting to happen, but once again, and like everything in life, it comes down to simple math. Sadly, there are no quick tricks with this one, unlike the positive odds, so if you want to do the calculations yourself (as opposed to just trusting the sportsbook to do it for you), you can follow this simple formula:

[alert variation=”alert-success”][(100/odds)+1] * $ bet = $ total payout[/alert]

As you can already tell, the difference in the positive and negative odds formulas is a small one – you just flip the “100” in the division. With the positive odds you divide the number by 100, while with the negative odds – you divide 100 by the odds number. If you remember this, you should have no problem calculating your bets payout, although not many people bother with all that math. Most people who bet online let the sportsbook calculate all that jazz for them, those betting at the Vegas sportsbook do it in their heads or use one of the hundreds of free odds calculators.

Now that you know how the betting odds work, let’s have a small side note. You may have noticed that you will never (or at least very rarely) see American betting odds like “-100”. This would be equivalent to the fractional odds 2/1. This sounds like a thing, so why do we see “-110” instead of “-100”? For example, if you bet $100 on 2/1 odds, you would double your money – makes sense, right? But if you were to bet on -110, you would only get $190.91, what gives?!? Fun fact, the 10 point difference in the American odds is what is called the vig. You can read explanation about what is the vig here, but in a nutshell, you pay those extra 10 points to the sportsbook for the privilege to be able to place a bet! You wish you didn’t know that, now, don’t you?

[alert variation=”alert-info”]Decimal Betting Odds[/alert]

Let’s allow our brain to cool off and close the explanation of how sports betting odds work with the simplest type – the decimal odds. Anywhere else in the world, save for the US, these are the type of odds you will see at the sportsbooks (or bookmakers, as they call them over the pound). They are as simple to calculate as you can get and take the form of a decimal number (duh), such as 2.30 or 1.05, etc. In order to calculate your total payout, all you have to do is multiply your bet by the odds, and that’s it. So, a $10 bet on 2.40 odds is: 2.40 * $10 = $24. It doesn’t get any easier than this! Here is a piece of trivia, if you want to be super nerdy and impress your friends (or get punched in the face, depending on the crowd you roll with): the decimal odds in Europe are often called “coefficient” instead of “odds”.