Fractional odds are most commonly used in the UK and Ireland with the majority of UK betting sites using them to express the probability of an outcome.

Betting sites will use fractional odds to indicate the chances of something occurring and are most commonly displayed as two numbers separated by a slash.

    • Examples of fractional odds – 5/4, 6/5, 10/11 and 25/1

Although some fractional odds can be extremely straightforward (2/1), others require a little more brain power in order to calculate your sports betting returns (10/3).
Luckily, punters can use one of the many fractional odds calculators available online in order to work out how much they will receive for a winning selection.

Evens (2.00) is often commonly displayed as 1/1 in fractional odds betting. Odds-on selections will have the higher number of the right (eg 4/5), whereas Odds-against selection will display the higher number of the left-hand side (eg 6/4)

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How to Calculate Your Returns Using Fractional Odds

Fractional odds make it extremely straightforward to calculate your returns. The number on the right-hand side of the slash is the amount you would be betting, whereas the corresponding number of the left-hand side is the amount that you would win.

Example 1:

£10 on odds of 3/1

For every £1 (1) that you bet on these odds, you will get £3 (3) in return.

In order to work out your returns for a £10 bet:

£10 x 3 = £30 profit. Unlike decimal odds, your stake is not included here so total returns:

£30 profit + £10 stake = £40 return

Unfortunately, not all fractional odds are as straightforward and maths is often required in order to calculate your returns.

Example 2:

£10 on odds of 13/2

For every £2 (2) that you bet on these odds, you will get £13 (13) in return

NOTE: You are not required to exclusively bet £2 at these odds

In order to work out your returns for a £10 bet:

Divide the number on the left by the number on the right (13 divided by 2). This will help calculate your returns for a £1 stake.

13 divided by 2 = 6.5

These odds are essentially 6.5/1

£10 x 6.5 = £65.00. Once again, this does not include your original stake.

£65 profit + £10 stake = Total returns of £75

The formula to use in order to calculate all fractional odds is:

Number on the left-hand side

Number on the right-hand side

                        X

                    Stake

How to Convert Fractional Odds to Decimal Odds

It is incredibly simple to convert fractional odds to decimal odds. Although most UK betting sites will allow users to switch between the two, it doesn’t take long to complete the calculations.

In order to convert fractional odds to decimal odds, you must divide the number of the left-hand side by the number on right-hand side (see above) and add 1.

Example 1:

£10 on Odds of 5/2

5 divided by 2 = 2.5

+ 1

= 3.5

5/2 in decimal odds is displayed as 3.5

Example 2:

£10 on odds of 15/2

15 divided by 2 = 7.5

+1

= 8.5

15/2 in decimal odds is displayed as 8.5

The formula to use in order to convert fractional odds to decimal is:

Number on the left-hand side

Number on the right-hand side      

                  + 1

Fractional Odds to Decimal Odds Table

Fractional Decimal
1/2 1.50
4/5 1.80
1/1 2.00
6/4 2.50
7/4 2.75
2/1 3.00
3/1 4.00
10/3 4.33
4/1 5.00
13/2 7.5
7/1 8.00
10/1 11.00
12/1 13.00
20/1 21.00
50/1 51.00
100/1 101.00
1000/1 1001.00

How to Convert Fractional Odds to American Odds

Similar to when converting decimal odds to American odds, there are two different methods required. Method 1 is used for odds-on selections (4/5 or 5/6) with Method 2 covering odds-against selections (4/1 or 6/4 – anything bigger than 1/1)

Odds-on Example:

£10 bet at 4/5

Convert the fractional odds to decimal (see above) and then multiply by 100.

4\5  x 100   = 80

This calculation gives us 80.

Divide -100 by this number = -1.25

-1.25 is the American odds equivalent of 4/5

Odds-against Example:

£10 bet at odds of 6/4

Convert the fractional odds to decimal (see above) by multiplying by 100

6\4  x100 = 150

+150 is the American odds equivalent of 6/4

In order to convert fractional odds into American odds, you will need to use the following formulas:

Odds-on:

-100 / (Fraction converted to Decimal)

Odds-against:

(Fraction converted to Decimal) x 100

Fractional To American Odds Table

Fractional American
1/5 -500
2/9 -450
¼ -400
2/7 -350
3/10 -333.3
1/3 -300
4/11 -275
4/9 -225
1/1 100
5/4 125
11/8 137.5
10/1 900
11/1 1000
20/1 2000
50/1 5000
100/1 10000
1000/1 100000

Calculating Sports Odds for Different Markets

In the UK, football betting is extremely popular and it is incredibly simple to calculate your returns using fractional odds. Most UK bookmakers will price up soccer games using fractional odds.

In a game of soccer, there are three possible outcomes – home win (1), Draw (X) or away win (2)

Typically, a home win will be a priced at shorter odds and it isn’t uncommon to see home teams at an odds-on price (e.g 7/10 or 8/11)

To calculate your returns for an 8/11 home win:

8 divided by 11 = 0.72

0.72 x £10 stake

Profit £7.20+ £10 stake

Total returns = £17.20

A draw will often be priced up at a larger price as the chances of this occurring are deemed less likely.

To calculate your returns on a 5/2 draw

5/2 = 2.5

2.5 x £10 stake = £25

Profit £25 + £10 stake

Total returns = £35.00

In NFL or Basketball, some UK betting sites will price up each outcome using fractional odds, although some operators do frequently use decimal odds as well. This can also be converted into American odds.

In NBA, the points spread will be set by the bookmaker and is often based on recent form. During the regular season, there is often a major disparity between the two teams, however during the play-offs, the points spread tends to decrease. Most bookmakers will opt to make the points spread market a 50/50 outcome and each +/- points will be 10/11

£10 on a team to overcome the -10 points spread at 10/11, your returns will be calculated as:

10 divided by 11 = 1.91

1.91 -1 = 0.91

0.91 x £10 = £9.10

Profit £9.10 + £10 stake

Total returns = £19.10

The total points market also tends to be priced up as a 50/50 chance and each outcome will also typically be priced at 10/11. Once again, it is fairly straightforward to calculate your returns.

£10 on Over 206 total match points at 10/11, your returns will be

 

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