How to read and analyze American format betting odds

With legal sports betting spreading across North America, more and more sports fans are visiting the sportsbook and attempting to read American format betting odds for the first time. As a beginner, looking at the long list of numbers and symbols can be overwhelming, but in reality, reading sports betting lines is quite simple. All it takes is a little practice.

American format betting odds are used across a massive variety of sports and leagues. Once you understand how to read and analyze these betting lines, you’ll be able to make almost any wager at the sportsbook.

At the most basic level, being able to understand American format betting odds relies on just two principles.

1. If the number is listed as a positive number, that is how much you can win from a $100 bet.
2. If the number is listed as a negative number, that is how much you need to bet to win $100.

Getting a grasp and understanding of those two concepts will give you the basic tools that you need to navigate any sportsbook.

Why are odds used in sports betting?

To start, it’s important to understand why odds are used in sports betting. In any sporting event, there are always different outcomes possible. The probability of all of those unique outcomes occurring usually has a large range. Odds allow sportsbooks and bookmakers to assign probabilities to each outcome, rewarding bettors who correctly predict more unlikely results with a higher return.

For example, if two teams of completely uneven strength play against each other, odds must be used to facilitate sports betting. Let’s say that the USA’s national basketball team was going to play against your former high school’s grade eight basketball team. Without odds, there is little doubt that any sane person would bet their money on the USA national team.

However, with odds, sportsbooks can facilitate bets and get action on both sides, even in a lopsided matchup such as the one above. For example, if you had to bet $4 million to potentially win $1 on Team USA while a $1 bet on the Tinseltown High Cougars would potentially win $5 million, you might think about risking a dollar on the 13-year-olds to beat LeBron James and friends.

This is the purpose of odds when it comes to sports betting. Without odds, there would be no incentive to bet on any outcome other than the most probable. Depending on where you are in the world or what sport you’re betting on, odds can take many different forms. For people in North America, American format betting odds are what you’ll see most.

How to read American format betting odds

When you visit a sportsbook in North America, no matter if it’s in-person or online, you’re going to be greeted by a massive list of teams and numbers. In Canada and the United States, the default format is known as American format betting odds and looks like the following with a plus (+) or minus (-) sign followed by a number.

American format betting odds are based on a standard unit size of $100. This does not mean that you need to deposit or bet that amount but when doing base calculations, it’s easiest to do them with this value.

The first thing that you need to look at is if the number is positive or negative. In the example above, all the numbers are positive. In the American odds betting format, when a betting line is denoted as a positive number it represents how much you can win from a $100 bet. For example, if you bet $100 on the Los Angeles Dodgers to win the World Series and it was a successful wager, you would receive $450 in winnings plus your $100 stake for a total of $550.

On the other hand, sometimes betting lines can be shown as a negative number with a minus (-) sign in front. If a betting line is represented as a negative number, this shows how much money you need to stake to win $100. For example, if you saw a betting line of -135, you would need to bet $135 to win $100, returning a total of $235 if your wager wins.

What does the plus (+) sign mean in American format betting odds?

The plus sign is used to show lines that have an implied probability of 50% or less. When you see a line that has the plus (+) sign in front of it, you know that it represents how much you can potentially win with a $100 bet.

If you don’t want to bet $100, that’s no issue. All you need to do is a little bit of math to see how much you stand to win. For example, if you’re betting $10 on a line that’s +125, you’ll win $12.5 instead of $125, returning a total of $22.5 after the stake is included.

What does the minus (-) sign mean in American format betting odds?

Lines that have a minus (-) sign in front of them are used for betting selections that have an implied probability of more than 50%. The return on these betting markets will not be as high as betting on lines that have a plus (+) sign in front.

When betting on selections with a minus (-) sign in front, know that the number represents how much you must wager to win $100. Again, this does not mean that you need to bet $100, instead, it’s simply providing the line that can then be matched to whatever stake you would like.

What are the other type of popular ways to display betting odds?

While American format betting odds are standard in North America, there are a few other ways that betting lines are commonly displayed. If you’re using an online sportsbook, you can toggle between these different options and pick the one that you like best.

The other two most popular ways to display betting odds include the decimal format and the fractional format. These are more commonly seen in Europe but some sports bettors in North America may find that they like them better.

Decimal betting odds

The decimal betting odds format is perhaps the easiest to understand. All odds are displayed as a decimal. To figure out your total return with decimal betting odds, you simply multiply your stake by the given decimal. The return of that equation will tell you the total amount that you stand to return if your bet is successful, including your stake and winnings.

As you can see in the screenshot above, decimal format odds are quite easy to read. You can just multiply however much you want to bet by the number given and figure out how much you stand to win after a successful wager.

American betting odds into decimal formula

If you’re looking at a sportsbook with American betting odds but you feel more comfortable working in decimal format, you can do a simple conversion. Knowing how to do this can be especially helpful if you’re betting at an in-person sportsbook as many use American odds in North America. Below you can find the American betting odds into decimal formula.

• For positive American format odds: (Positive American format betting odds / 100) + 1 = Decimal odds
• For negative American format odds: (100 / negative American format betting odds) + 1 = Decimal odds

To proceed with the American betting odds into decimal formula, the first thing you need to do is check if the American odds betting line is positive or negative. If it’s positive, follow the steps below.

1. Find the line that you want to convert, let’s use +138 as an example.
2. Add the line to the American betting odds into decimal formula and finish the math.
3. (138/100) + 1 = Decimal odds
4. (1.38) + 1 = Decimal odds
   
   Answer = 2.38

If you’re looking at a negative American odds betting line, simply use the second formula designed for this situation. In this case, let’s use -138 as our example.

1. Find the line that you want to convert, in this case we are using -138.
2. Use the proper formula to convert negative American odds betting lines into decimal format.
3. (100/135) + 1 = Decimal odds
4. (0.74) + 1 = Decimal odds
   
   Answer = 1.74

Fractional betting odds

The third type of way to display betting odds that is quite common is the fractional format. This is another format that is quite easy to understand. Just as you would with the decimal odds, all you need to do to calculate your total return when using fractional odds is multiply your stake by the fraction given.

For example, let’s say that you were going to bet on the Atlanta Braves to win the World Series. If you bet $100 on them to win at 6/1, you would stand to win $600. When you include your stake of $100, you would be returned a total of $700.

American betting odds into fractional formula

If you’re looking to turn American betting odds into fractional format, you can do so with the American betting odds into fractional formula. This is an easy formula to remember. The most important step is to make sure that you are using the right American betting odds into fractional formula depending on if the line is positive or negative.

• Positive American odds to fractional formula: (American odds / 100)
• Negative American odds to fractional formula: (-100 / American odds)

As you can see, it’s not very difficult to do the conversion between the two. Let’s say that you want to use the American betting odds into fractional formula for a line that’s at +250. It would look something like this.

1. Input the betting line, +250 in this case, into the proper formula.
2. (250/100)
3. The answer that you would get is 2.5/1

How to convert American format betting odds into probabilities

Besides converting betting odds across different formats, it’s also useful to know how to convert odds into probabilities. Any odds that you see can always be converted to a probability.

Knowing how to convert odds into probabilities is a useful skill to have. You can use it to guide your bets as if you find a large difference between the probability that you have assigned to an outcome and the odds, then that means it’s likely worth placing a wager on.

• For positive American odds: (100 / (American odds +100)) * 100 = Probability
• For negative American odds: Multiply the value by -1 and use the positive odds in the above formula.

This is a little bit more complicated than converting American format betting odds into the other formats but still not too hard. After a little bit of practice, it becomes quite easy to make this calculation very quickly.

For positive odds, which you will always be using after multiplying any negative odds by -1, simply plug the line into the formula above and perform the calculations. Let’s take a look at an example using a betting line of +275.

1. To start, put your betting line into the formula. We are using +275 for this example.
2. (100 / (275 +100) * 100 = Probability
3. Next, continue with the math.
4. (100 / 375) * 100 = Probability
5. (0.2666) * 100 = Probability
6. The implied probability of a +275 line is 26.66%

What is vigorish and why does it matter?

A key concept to familiarize yourself with in sports betting is that of vigorish. Vigorish, also referred to as “the vig” or “juice”, is the house edge that is put into every line. It’s the reason that sportsbooks make money no matter what happens in the sports world.

You can think of vigorish as the price that you are paying to place the bet. For example, when you look at most spread betting lines, the odds for either side will be -110. This means that no matter which side you’re betting on, of which both have equal probabilities according to the odds, you’re only getting $10 back for every $11 you gamble. That extra $1 is the vigorish and what the sportsbook keeps for performing its task.

Let’s say that somehow the Los Angeles Lakers were going to play against themselves. Every player would be cloned and they were going to play a game on a neutral site. Technically, there should be nothing separating these two teams and each side should have a 50/50 chance of winning. However, the odds at the sportsbook would tell you differently.

In this scenario, the odds for each side would likely be set at -110. This means that if 10 people bet on each side, the sportsbooks could use the losing bets to pay out the winners and still have $1 per person left over to keep as a profit.

It’s important to consider the vigorish when you’re making your bets. When you convert a betting line into a probability, know that that number is not the true probability that the sportsbook has assigned the event. That’s because there is additional vigorish so the probability is lower than the betting line suggests.

American format betting odds FAQ