Understanding how betting odds work is a vital skill to possess if you want to make a consistent profit from your betting activities.
In the United Kingdom and Europe, the two most prevalent type of betting odds are fractional and decimal, both of which produce the same result.
Most traditional bookmakers have historically used fractional odds, while decimal odds tend to be found on betting exchanges.
Read on as we show you how betting odds work and help you get to grips with the differences between fractional and decimal prices.
Fractional Odds
Fractional odds have their roots in horse racing in the UK and Ireland, with most bookmakers using them to display prices for each race.
These types of odds have also been used across the sporting spectrum and show how much profit a bettor will make against their stake if their selection is successful.
In simple terms, the number on the right of the fraction is the amount you must stake to win the figure on the left.
For instance, a £1 stake on a horse to win a race at odds of 2/1 would return a £2 profit if it finishes first. The punter would therefore receive £3 (£1 stake + £2 profit).
Decimal Odds
The launch of betting exchanges sparked a change in the way odds are displayed, with decimals used to show the prices on offer for each event.
Decimal odds are generally displayed to two decimal places, so if you place a £10 bet at odds of 3.50 your return would be £35 (£10 stake x 3.50 = £35).
Although it may take a while for punters more familiar with fractional odds to understand decimal odds, they are a little easier to understand.
As opposed to displaying the profit you make on your stake, they convey the exact return you would receive if a selection is successful.
Converting Fractional to Decimal Odds
To convert fractional odds to decimal, you must divide the first figure by the second figure and then add 1.00.
For instance, fractional odds of 11/4 is 11 divided by four which equals 2.75. If you add 1.00, you are left with decimal odds of 3.75.
Using the same odds, if you place a £4 bet at fractional odds of 11/4 and your selection is successful your return would be £15 (£4 stake + £11 profit = £15).
Placing a £4 bet at decimal odds of 3.75 also returns £15 (£4 stake x 3.75 = £15) if your selection wins its particular event.
Converting Decimal Odds to Fractional
It is worth noting that not all decimal odds translate to fractional odds that are recognisable as the ones used traditionally in betting markets.
For instance, if you have decimal odds of 1.80 this equates to fractional odds of 4/5, but if the price shortens to 1.74, this equates to a strange-looking 37/50.
This anomaly is due to the traditional nature of the fractions used by bookmakers, which weren’t to the same full scale found in decimal odds.
This method allowed bookies to build an additional profit margin into their books and shave extra value off the prices they offered to punters.
Using Odds Conversion Tools
There are numerous online sites which offer punters the chance to convert odds easily using innovative betting tools.
These often have four fields – fractional odds, decimal odds, American odds and implied probability (percentage).
To use an odds converter, enter a value into any field and it will automatically convert the odds into all of the other formats.
Using an odds convertor is a great way to take the hassle out of calculating odds, particularly if the betting site you visit displays them in a way you are unfamiliar with.
Converting Fractional odds to Decimal – The Final Word
If you have a simple grasp of mathematics, it is extremely easy to convert fractional odds into decimals.
However, if the numbers involved leave you feeling baffled, the following chart will help!
| Fraction | Decimal | Fraction | Decimal | Fraction | Decimal | ||
| 1/5 | 1.20 | 5/4 | 2.25 | 5/1 | 6.00 | ||
| 2/9 | 1.22 | 11/8 | 2.38 | 11/2 | 6.50 | ||
| 1/4 | 1.25 | 7/5 | 2.40 | 6/1 | 7.00 | ||
| 2/7 | 1.29 | 6/4 | 2.50 | 13/2 | 7.50 | ||
| 3/10 | 1.30 | 8/5 | 2.60 | 7/1 | 8.00 | ||
| 1/3 | 1.33 | 13/8 | 2.63 | 15/2 | 8.50 | ||
| 4/11 | 1.36 | 7/4 | 2.75 | 8/1 | 9.00 | ||
| 2/5 | 1.40 | 9/5 | 2.80 | 17/2 | 9.50 | ||
| 4/9 | 1.45 | 15/8 | 2.86 | 9/1 | 10.00 | ||
| 1/2 | 1.50 | 2/1 | 3.00 | 10/1 | 11.00 | ||
| 8/15 | 1.53 | 11/5 | 3.20 | 11/1 | 12.00 | ||
| 4/7 | 1.57 | 9/4 | 3.25 | 12/1 | 13.00 | ||
| 8/13 | 1.62 | 12/5 | 3.40 | 13/1 | 14.00 | ||
| 4/6 | 1.66 | 5/2 | 3.50 | 14/1 | 15.00 | ||
| 8/11 | 1.72 | 13/5 | 3.60 | 15/1 | 16.00 | ||
| 4/5 | 1.80 | 11/4 | 3.75 | 16/1 | 17.00 | ||
| 5/6 | 1.83 | 3/1 | 4.00 | 18/1 | 19.00 | ||
| 10/11 | 1.91 | 10/3 | 4.33 | 20/1 | 21.00 | ||
| Evens | 2.00 | 7/2 | 4.50 | 25/1 | 26.00 | ||
| 11/10 | 2.10 | 4/1 | 5.00 | 33/1 | 34.00 | ||
| 6/5 | 2.20 | 9/2 | 5.50 | 100/1 | 101.00 |