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How to Read Betting Odds

Confused about how to read betting odds? We've prepared specific scenarios, examples, and explanations to help you understand betting odds better.

A. Tzamantanis

Sports Betting Editor

Last Updated: 2024-05-29

Fact checked by:

Jon Young

Sports Betting Writer

6 minutes read

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Table of Contents

To have the best possible experience at the top sports betting sites, you need to know how to read betting odds.

Today, we’re going to tell you how to read odds in betting, whether it’s in decimal, fractional or American formats. Plus, we’ll give you some great examples, so that you’re confident the next time you want to place a bet on your favourite sports.

Types of Odds Formats

Betting odds come in various formats, each with its own way of representing the likelihood of an outcome and the potential payout. There are three main types of odds formats, which we’ll look into now.

American Odds

Also known as moneyline odds, American odds are predominantly used in the United States. They are represented using either a positive (+) or negative (-) symbol.

Positive odds (+): Positive odds indicate the potential profit from a £100 wager. For example, if the odds are +150, you would win £150 on a £100 bet, making your total return £250 (including your initial stake)
Negative odds (-): Negative odds represent the amount you need to wager to win £100. For instance, if the odds are -200, you would need to bet £200 to win £100, resulting in a total return of £300 (including your initial stake)

Calculating potential winnings with American odds involves simple arithmetic based on whether the odds are positive or negative.

Decimal Odds

Decimal odds are the most common format used in Europe and Australia. They represent the total return, including both the stake and the profit, for every £1 wagered.

For example, if the odds are 2.50, you would win £2.50 for every £1 bet. To calculate the total return, simply multiply your stake by the decimal odds. So, if you bet £10 at odds of 2.50, your total return would be £25 (£10 stake x 2.50 odds).

Fractional Odds

Fractional odds, commonly used in the UK, are represented as fractions. The first number indicates the potential profit, while the second number represents the stake required.

For instance, if the odds are 3/1, you would win £3 for every £1 bet. To calculate the total return, add the profit to the stake. So, if you bet £10 at odds of 3/1, your total return would be £40 (£30 profit + £10 stake).

Understanding Favourites and Underdogs

In sports betting, understanding the concept of favourites and underdogs is crucial for interpreting odds and making informed decisions. Here's how positive and negative odds indicate favourites and underdogs

Positive Odds (+) for the underdog

Positive odds represent the potential profit from a £100 wager. They are typically assigned to the underdog in a matchup, indicating a lower perceived probability of winning. A successful bet on the underdog with positive odds results in a higher payout relative to the amount wagered.

Negative Odds (-) for the favourite

Negative odds show you the amount needed to wager to win £100. They are typically assigned to the favourite in a matchup, indicating a higher perceived probability of winning. A successful bet on the favourite with negative odds results in a lower payout relative to the amount wagered.

Reading Betting Odds: Examples

To understand how to read sports betting odds properly, let’s look at an example of each odds format to illustrate how to calculate winnings based on a specific bet amount.

American odds example

Positive Odds of +150: If you bet £100 on the underdog with odds of +150 and they win, you would receive a payout of £250 (£150 profit + £100 stake)
Negative Odds of -200: If you bet £200 on the favourite with odds of -200 and they win, you would receive a payout of £300 (£100 profit + £200 stake)

Decimal Odds Example

Decimal odds of 2.50: If you bet £10 on a selection with odds of 2.50 and it wins, your total return would be £25 (£15 profit + £10 stake)

Fractional Odds Example

Fractional odds of 3/1: If you bet £10 on a selection with odds of 3/1 and it wins, your total return would be £40 (£30 profit + £10 stake)

Odds and Probability

Understanding how odds reflect the probability of an event is an essential part of sports betting. With that in mind, let’s look at the two concepts in more detail.

Higher odds: These show a lower perceived probability of the event occurring. For example, if the odds for a team winning are 5/1, it suggests that the sportsbook believes there's a lower chance of that team winning compared to a team with odds of 2/1
Lower odds: These indicate a higher perceived probability of the event occurring. For instance, if the odds of a team winning are 1/2, it suggests that the sportsbook believes there's a higher chance of that team winning compared to a team with odds of 3/1

How sportsbooks set odds

Sportsbooks use a combination of factors to set odds, including:

Statistical analysis: They analyse historical data, team/player performance, injuries, weather conditions, and other relevant factors to assess the likelihood of different outcomes
Market demand: Sportsbooks consider the betting patterns of their customers. If there's heavy betting on one side, they may adjust the odds to balance their books and minimise their risk
Competitor odds: Sportsbooks may also look at the odds offered by their competitors to ensure competition in the market
Expertise and experience: Experienced oddsmakers use their knowledge of the sport and industry insights to set accurate and competitive odds
By setting odds that accurately reflect the perceived probability of an outcome, sportsbooks aim to attract balanced betting action on both sides of a wager, ensuring a profit regardless of the outcome.

Identifying overvalued and undervalued odds

Overvalued odds: If you believe the probability of an outcome is higher than what the odds suggest, you may consider the odds overvalued. In this case, you might find value in betting on that outcome
Undervalued odds: Conversely, if you believe the probability of an outcome is lower than the odds suggest, you may believe that the odds are undervalued. In this case, you might avoid betting on that outcome as it offers poor value

Calculating implied probability

You can calculate the implied probability of an outcome from its odds using the following formulas:

Decimal odds: Implied probability = 1 / decimal odds
Fractional odds (e.g. 2/1): implied probability = 1 / (fractional odds + 1)

Comparing the implied probability to your own assessment of the likelihood of an outcome can help you identify value bets in the market.

For more betting tips, make sure you come and visit us here at SportsBoom. We keep you up to date with all the latest news, reviews and guides.

What is an Odds Table in Betting?

An odds table is a handy reference tool that displays different types of odds (decimal, fractional, and American) and their implied probabilities. It helps you quickly compare and understand various odds formats, making it easier to make informed betting decisions.

Odds charts are particularly useful for seeing how different bookmakers might offer different odds on the same event, letting you find the best value.

An odds list can also serve as a learning aid for those new to betting, providing a clear and easy-to-understand comparison of odds and probabilities.

Here’s an example, and as you’ll see, you can easily cross-reference such things as 2/1 odds in decimal, 1/2 odds as decimal and 1/1 odds in decimal etc.

Odds Table in Betting

Fractional	Decimal	American
1/5	1.2	- 500
1/2	1.50	- 200
1/1	2.00	+ 100
2/1	3.00	+ 200
5/1	6.00	+ 500
10/1	11.00	+ 1,000
20/1	21.00	+ 2,000

For more information about understanding sports betting odds and popular bet types, make sure you always come to us here at SportsBoom. We keep you up to date with our news, reviews and guides.

Alyx TzamantanisSports Betting Editor

With 10 years of experience in content writing, Alyx has produced countess guides, reviews and articles covering a wide range of topics in the iGaming industry. She loves anything to do with online casinos, as well as UK and international sports betting.