In this article we want to speak about how to convert odds from fractional to decimal and the opposite way, and we want to show you show to convert a percentage probability into odds so you can be more well informed about betting odds and the bets you make on football matches.

First of all we need to write a little bit about understanding what chance is. It’s the likelihood of something happening, usually shown in percentages. When we see it expressed as a percentage we call it probability.

Let’s say we have a dice. You have a 1 in 6 chance of any number being rolled. The chance of it being one of the six numbers is equal. This means that if we divide 100% by 6, then we get 16.66%, this is the probability of any of the numbers being rolled.

There are three steps to converting betting odds

1. First you need to understand what format are the odds in that you’re looking at. Are they Fractional or Decimal? Fractional odds look like this: 1/2, 7/4, 11/12, 1/1, etc. Decimal odds are 1.90, 2.75, 3.65, etc.

2. Converting the odds to the implied probability.

3. Converting the implied probability to betting odds.

For example, decimal odds of 2.00 has an implied probability of 50% which can then be converted to fractional odds of 1/1.

Converting Decimal Odds to Implied Probability

Let’s start with decimal odds.

Manchester United take on Leicester City this weekend at Old Trafford, the Red Devils are currently around 1.85 to bag the three points. So, this means that for every £1 you bet you’ll win £0.85.

Converting these odds is very simple; implied probability = 1/ decimal odds. So 1/1.85 = 0.540, change that to a percentage and it’s 54%. Simple as that.

Converting Fractional Odds to Implied Probability

Fractional odds are still used widely in Britain and Ireland. Although many betting sites now will display their odds in decimal only, the large players in the UK and Ireland will also show their odds in fractions.

Let’s have an example, if there’s a greyhound running tonight in Henlow priced at 7/4 to win what this means is that for every £4 you bet you’ll receive £7 plus your stake back if the hound wins the race.

To convert fractional odds to implied probability you need to divide the denominator by the denominator + the numerator. So, in our example we have odds of 7/4.

7/4 = 4/(4+7) = 4/11 = 0.3636 = 36.36%

How To Convert Percentage Probability into Betting Odds

Arsenal are away to Watford this weekend and you think Arsenal have a 75% chance of winning the match. To convert a percentage to decimal odds you just divide it by 100. So 100/75 is 1.33.

To convert a percentage to fractional odds is a bit more long winded; you need to divide 100 by the percentage probability and then take one away, so in our 75% example, it would look like this: 100/75 = 1.33 - 1 = 0.33 which is 33/100.

Knowing how to convert odds between decimal odds and fractions is a handy tool to have in your betting arsenal and converting odds to implied probability and the opposite way will certainly lead you to making better, more-informed betting tips.