Fractional Odds Explained

Fractional odds are the preferred type of betting odds in the UK, while decimal odds are more used in Europe and American Odds in the United States.

They are represented in fraction format like this: ½ odds.

Fractions tend to confuse math-haters, but they are quite simple really.  A 2/5 fraction means a 100% is divided in 5 equal pieces, or 20%. The number on top tells you your value, which is two pieces of 20% or 40% in value. So for a bet with odds of 2/5 you can expect a profit of 40% of your investment.

Note of Importance: A big difference from decimal odds is that fractional odds do not include the stake, decimal odds usually do. This is a good thing, as you get used to calculating your profits without the stake involved, which inflate your real winnings.

Fractional Odds Calculation: Stake * Fractional Odds = Winnings without Stake.

Fractional Odds Calculator

There are many online fractional odds calculators online, the one we like to work with is OddsChecker for its simplicity, and it’s free. When we use this calculator it’s mainly to figure out odds from tipster tips that publish the possible profits but do not mention the odds.

Make sure to take odds above 2/5 or 40% in value.

Fractional Odds to Decimal

Personally, the author of this article prefers to use decimal odds above all other, I think fractional odds require one step more than decimal´s, but they are practically the same. In the end, you get accustomed to whatever method you use. So here is how you transform fractional odds into decimal:

Let’s use a live example from Bet365:

Stake: £20.00

Manchester United vs West Ham   

  • Manchester United 4/9 odds
  • Draw 10/3 odds
  • West Ham 6/1 odds

Each of those market options are for either team to win or a draw. Lets begin analyzing the odds for United.

Manchester United to Win at 4/9… If you finish the division you get 0.444 and this would be your decimal odds without the stake, or 45% of potential profits. To know your winnings simply do the multiplication.

(£20.00 * 4/9) = £8.89

If you like you can add the stake and your total return would be £28.89 pounds.

*Watch the Bet365 betting slip screen shot which does the calculation for you, and the result is the same.

You can tell why I prefer decimal odds, it is easier to tell what the profit level will be, in this case 0.444 was roughly 45%, while I have a great difficulty telling that from 4/9. Lets continue by doing the West Ham odds.

West Ham to win at 6/1… This one is easy because the decimal odds would be a 6, your payout would be 6 times whatever you bet.

(£20.00 * 6/1) = £120.00

Including the stake £20.00 + £120.00 = £140.00

Handsome reward, isn´t it? I bet you can tell who the favorite is. By far Manchester United is the big favorite to win the game, which is why West Ham pays like 15 times more.

How to Tell Favorites from Longshots with Fractional Odds

If Manchester United was a favorite with 4/9 odds and West Ham a longshot with 6/1 odds, can you see the difference between numerator and denominator?

  • The favorite will have a HIGHER denominator.
  • The longshot will have a HIGHER Numerator.

Selecting Value Bets in Fractional Odds

Fractional odds to decimal

Value bets are those that offer a nice reward for the risk you take. If you are serious about betting I suggest taking a read to our full article on Value Betting, but as a quick tip…

Only take bets that offer 45% and above in value, but make sure the result is almost guaranteed.

In the above example I would only take the bet for Manchester United if:

  • No main player injuries
  • They come from a solid past performance and have done so in the last 3 matches
  • It is not around Euro Cup qualifiers or World Cup qualifiers, international players are tired or with their mind somewhere else.

If any the three of the above come into play then you might consider taking the longshot bet on West Ham is their stats are not bad. You won´t get a better chance, and hell, it is a 6x payout for a simple straight win bet.

Another Way to Calculate Fractional Odds – Reciprocal Method

Real Madrid is facing Sevilla FC at home

The odds for the game given by Bet365 are shown below:

Real Madrid Win: – 3/5
Draw: – 7/4
Sevilla win: – 2/1

Reciprocal addition is more complex and confusing than simply turning the division into a decimal number, but some websites teach it this way for reasons I can´t comprehend:

Real Madrid win: 3/5
= (3+5)/5, Add the denominator to the numerator
= 8/5 = 5/8, taking reciprocal
= 0.625 * 100 =62.5%, so the betting website is predicting a 62.5 % chance for Real Madrid to win the match.

*Doing the same calculation by simply dividing numerator/denominator way we get 60%. So I am not entirely convinced this method is accurate.