By understanding the different odds formats bookmakers and exchanges offer, bettors will be able to compare odds across providers irrespective of format to find where the best value is.
Bookmakers and exchanges offer a number of different odds formats. No matter the format used, the probability is always the same. It’s just the presentation that differs.
Familiarity, nationality, the bookmaker/exchange used or the sport bet on can all determine which odds format bettors prefer.
When you can understand each odds format and calculate your payout, you’re better placed to compare the odds on offer across bookmakers and exchanges, allowing you to find best value quickly.
Betting odds as a percentage
Betting odds represent the chance an event will occur - the probability. In any event, each outcome has a chance of occurring. Odds are simply an interpretation of those chances.
However, odds are not normally represented as percentages, despite displaying the implied probability of an outcome better than any other format. This is because they are harder to compare quickly.
The return using percentage odds is calculated by first converting to decimal odds and then multiplying by stake.
(100 / percentage) * stake = return (including stake)
Below is an example of how to calculate your return using percentage odds:
West Brom to beat Peterborough 1-0: 11.4%
To calculate the return from a £50 bet we have:
This return includes your original stake giving a profit of £388.60
What are decimal odds?
The decimal odds format represents the potential return of a bet including stake. Decimals are more common as it’s the easiest format to compare prices between bookmakers and exchanges.
The potential return of decimal odds is simple to calculate. Just multiply the amount you wish to bet by the decimal odds offered.
odds * stake = return (Including stake)
Below is an example of how to calculate your return using decimal odds:
Man City: 2.10
To calculate the potential return on a £100 bet on Man City to win would simply be:
As this includes your original £100 stake the potential profit is £110.
What are fractional odds?
Fractional odds are most popular in the UK and particularly on horse racing, but are becoming less favoured due to the difficulty comparing them against other odds formats.
The odds displayed show the amount of profit you would receive for a winning bet relative to your stake.
Fractional odds are displayed as 10/1 or 7/2. For odds on selections fractional odds appear the other way around; 1/10 or 2/7.
The simplest way to understand this format is:
How much you will win / how much you stake
To calculate your potential returns from fractional odds, you can use this simple equation:
((numerator/denominator) +1) * stake = return
Let’s use an example horse racing card to showcase how to calculate a return using fractional odds:
Razin' Hell: 7/1
To calculate the potential return on a £100 bet on Razin' Hell to win would simply be:
What are American odds?
American odds, also known as money line or US odds, are expressed with either a positive or negative number. A negative number indicates what you must bet to make £100 profit, while a positive number indicates how much you might profit if you bet £100.
It’s important to understand that you don’t need to bet the amount equal to the money line - you can bet more or less, with the return linked to your stake.
The calculation to see a return on a negative money line is:
(100/negative money line odds) * stake
While the calculation to see a return on a positive money line is:
Positive money line odds * (stake/100)
Let’s use an example tennis match of how to place a bet using American odds:
US Odds on a tennis match
To calculate the potential return on a £30 bet on favourite Djokovic would simply be:
To calculate the potential return on a £175 bet on underdog Murray would be:
Apply this to betting
You now understand what the different odds formats are, and how to calculate the potential return for each. Applying this knowledge gives you the tools to compare odds across numerous bookmakers and exchanges, irrespective of what odds format is shown, so you can identify where the best price is.