# Converting Sports Betting Odds

The odds converter tool in this page will convert odds from any of the three main formats into the other formats.

It will also calculate the relevant implied probability too.

To use it, simply enter the odds you wish to convert in the appropriate box, and then click the “Convert Odds” button. It’s as easy as that!

If you came to this page specifically looking for a tool to

convert odds, then it’s likely that you already have a

fundamental understanding of what odds are and how they work in

relation to sports betting. If this is a subject that you’re not

particularly familiar with, however, then you might want to read

the following article from our beginner’s guide to sports

betting.

## Overview of Different Odds Formats

If you live in the United States, then simply knowing the

**moneyline odds** will suffice, as this is the primary format used

by the limited number of gambling sites available for US

residents. Likewise, if you live in the United Kingdom, then you

only really need to know how **fractional odds** work. If you live

in Europe, then the **decimal format** is the one that will be most

important for you to understand.

With all that being said, it’s still a good idea to be

familiarized with how each format works. Many online betting

sites will allow you to choose the format that their odds are

displayed in. Please keep in mind that the conversation may

round in their favor.. For example, most US friendly sites offer

moneyline odds of -110 when betting points spreads. If you

choose to bet in the decimal format instead, then you’ll often

be given odds of 1.90. The true conversion is 1.9091 though, so

you’ll potentially lose a small percentage of your winnings if

you bet based on their conversion.

Therefore, it can be an advantage to use the primary format

offered by an online bookmaker, which is why it pays to make

sure you understand each of the different formats. We’ve

explained them all below for you.

### American Odds/Moneyline Odds

Odds in this format are expressed as either a positive number

or a negative number. When they are a positive number, the

number represents how much in winnings is paid per $100 staked.

The following examples illustrate how positive moneyline odds

work.

When they are a negative number, the number represents the

amount of money that needs to be staked in order to win $100.

The following examples illustrate how negative moneyline odds

work.

Please see our article on calculating payouts from moneyline

odds for details on how to work out the potential winnings from

wagers using this format.

### Decimal Odds

This is the most popular odds format outside of the United

States and is sometimes referred to as European odds. It’s a

very simple format where the odds are expressed as a single

positive number, usually to two decimal places. This number

states how much a winning bet returns (including the initial

stake) for each unit wagered. The following examples illustrate

the decimal format in practice.

Our article explaining how to calculate payouts from decimal

odds will teach you how to work out the potential returns from

wagers placed using this format.

### Fractional Odds

Fractional odds are mostly used in the UK, but lately the

decimal format has been becoming more popular. Odds in this

format are displayed as a fraction, as the name suggests. The

first number of the fraction shows how much you can win per the

second number staked. This sounds more complicated that it

actually is and the easiest way to understand this format is

simply to look at some examples.

Please note that when the second number of the fraction is

higher than the first, it means the odds are less than even

money. This is referred to as odds on (as opposed to odds

against), and is the equivalent of when moneyline odds are a

negative number or when decimal odds are a number less than 2.

## Odds Conversion Math

Our conversion tool is the easiest way to **change odds between
formats** but there will be times when you don’t have access to

it. When you’re at a Las Vegas sportsbook or a high street

bookmaker, you may need to be able to do these conversions in

your head. For this reason, we’ll run through the math required

to convert each format into all of the other formats.

### Converting Moneyline Odds

#### To Decimal

The calculations required to convert from moneyline odds

changes depending on whether the odds are positive or negative.

To convert positive odds into decimal odds, the following

calculation is required.

Example: Converting +175

(+175 + 100) / 100 = 2.75

For negative odds, we ignore the minus symbol and use the

following formula.

Example: Converting -110

(110 + 100) / 110 = 1.909

#### To Fractional

When converting from the moneyline format into the fractional

format, the calculations again depend on whether the odds are

positive or negative. To convert positive odds, you simply

create a fraction by putting the relevant number over 100 and

then simplifying the fraction if possible.

300/100 is simplified to 3/1

To convert negative odds, you create a fraction by putting

100 over the relevant number (ignoring the negative sign).

Again, you then need to simplify the fraction if possible.

100/110 is simplified to 10/11

### Converting Decimal Odds

#### To Moneyline

The method required to convert the decimal format over to the

moneyline format is dependent on whether the odds are greater

than 2.0 or not. We’ll look at how to convert odds of 2.0 or

less first. To start with, you have to carry out the following

calculation.

After doing this calculation, the odds are rounded and a

negative sign must be added.

100 / (1.95 – 1) = 105.25

To convert odds of greater than 2.00, you must start with the

following calculation.

To convert odds of greater than 2.00, you must start with the following calculation.

You then add a positive sign to the result, as shown in this

example.

(2.45 – 1) x 100 = 145

Positive sign added = +145

#### To Fractional

The first step in converting from decimal to fractional

format is to create a fraction by using the formula.

This will often create a fraction that includes a decimal,

which isn’t a proper fraction. To overcome this, the next step

is to multiply both sides of the fraction by 100. Finally, the

fraction needs to be simplified. The following example

illustrates this better than any written explanation can.

(1.45 – 1) / 1 = 0.45/1

Multiply both sides by 100 = 45/100

Simplified = 9/20

### Converting Fractional Odds

Before we get into the math involved here, you need to

understand the terms numerator and denominator. In this context,

the numerator is the first number in the fraction and the

denominator is the second number in the fraction. With odds of

2/1, for example, 2 is the numerator and 1 is the denominator.

#### To Moneyline

There are two methods needed for converting from the

fractional to the moneyline format. The first is for when the

numerator is greater than the denominator. The following formula

needs to be used in the beginning.

A positive sign then needs to be added to create the

moneyline odds, as per the following example.

(6 / 4) x 100 = 150

Positive sign added = +150

The second method is for when the denominator is larger than

the numerator. In these cases, the following formula needs to be

used.

A positive sign then needs to be added to create the correct

moneyline odds. This is illustrated in the following example.

100 / (2 / 5) = 250

Negative sign added = -250

#### To Decimal

Converting odds from the fractional format to the decimal

format is relatively simple and it requires just the following

formula.

(11 / 10) + 1 = 1.10

## Implied Probability Explained

Implied probability in relation to sports betting is

basically the implication of the odds as it relates to the

chances of an outcome happening. We’ll cover this in more detail

shortly, but first let’s look at how to calculate it. It’s

easiest to determine implied probability from odds in the

decimal format, using the following simple formula.

1 / 2.50 = 0.4

What this example shows us is that the implied probability of

2.50 odds is 0.40 (or 40% if expressed as a percentage). This

means that odds of 2.50 on any possible outcome imply that the

chance of that outcome happening is roughly 40%. So if, for

example, a tennis player is at 2.50 to win an upcoming match,

the implication is that he has a 40% chance of actually winning

that match.

You can read more about implied probability in this article on probability in sports betting. The article also

covers expected value, which is a related topic that you should definitely learn about if you want to be a

successful bettor.

## Understanding Vig

When looking at the odds set by bookmakers, it’s important to

recognize that implied probability is rarely an entirely

accurate reflection of the real chances of a wager winning. This

is because bookmakers always try to set the odds at levels that

are lower than they actually should be in relation to real

probability. If their view was that a soccer team had a 60%

chance of winning a match, for example, they wouldn’t offer odds

that exactly reflected that chance. Their odds would be lower,

as this is how they make money successfully.

By reducing the odds relative to the probability of an

outcome happening, bookmakers effectively charge a commission

for every wager they take. This commission is known as vig,

which is short for vigorish. It can also be referred to as the

overround or juice. It’s similar in some respects to the house

edge in casino games and it’s basically what gives the

bookmakers an advantage over their customers.

What sets the bookmakers’ advantage apart from the casinos’

advantage is that, unlike the house edge, it can be overcome. In

order to overcome it, though, you first need to understand

exactly how vig works and the effect it has in sports betting.

You should visit our page on the subject of how bookmakers make

money, as this is all about the methods that bookmakers use to

ensure they are profitable. Charging vig is one of these methods

that we explain thoroughly.