Do you know the different odds formats?  Do you understand what your return will be if your bet wins?  Bookie Ninja are here to help and advise with our BETTING ODDS EXPLAINED guide.


There are three main odds formats used and depending on website location across the world will generally determine which one is the default used on site.  You should also be able to find the option to update the displayed odds to your preferred format at each site

The three formats are;

FRACTIONAL – Good old fashioned Fractional Odds used mainly across Britain

DECIMAL – Mainly used across Europe and more commonly used now with the popularity of Betting Exchanges

MONEYLINE – Mainly used across US sites

Decimal odd are now the most common online but you should be able, on most sites, set to your preferred format.

Lets go through the main 2 format types in more detail;


Although Decimal odds are slowly catching up here, fractional odds are still the most commonly used format on UK sites.  Fractional Odds are when you see 2 numbers separated by a slash e.g.5/1.  This format allows you to calculate how much you will win in comparison to your stake.  The left side number is your winnings and the number on the right is the stake amount.

For example;

  • EVENS in Fractional format would be 1/1.  You Win 1 unit for every 1 unit staked.
  • 4/1 means you would win 4 units for every 1 unit staked
  • 1/4 means you would win 1 units for every 4 units staked

To calculate the chance of success (providing the odds are accurate) the formula is;


Using our examples above this would be;

  • 1/1 can be calculated as 1/(1+1) = 1/2 = 0.50 = 50% chance of success
  • 4/1 can be calculated as 1/(1+4) = 1/5 = 0.20 = 20% chance of success
  • 1/4 can be calculated as 4/(4+1) = 4/5 = 0.80 = 80% chance of success


Decimal odds are becoming increasingly popular due to it s relative ease to calculate returns and winnings.  Decimal odds odds are displayed in numerical form e.g 8.00.

Decimal odds allow you to easily calculate your total return for the bets placed, you simply multiply your stake by the Decimal odds offered.  To calculate your profit the formula would be;


Using the same examples as earlier;

  • Evens in Decimal for is displayed as 2.0.  For every £1 bet your return would be £2 and your profit would be £1
  • 4/1 in Decimal form is displayed as 5.0.  For every £1 bet your return would be £5 and your profit would be £4
  • 1/4 in Decimal form is displayed as 1.25.  For every £1 bet your return would be £1.25 and your profit would be £0.25

Bookie Ninja hopes this helps with your understanding of the 2 main odds formats used across online bookmakers.