Fraction Odds to Decimal, American, Probability (Converter)

Fraction Odds are typical for the UK and Ireland, and are often referred to as traditional odds. They are written with a slash “/”, and for example, the odds 3/1 reads “three-to-one”.

They represent the potential profit you can make relative to your stake. For instance, if you come across odds of 5/1, it means for every unit you stake, you stand to win five times that amount. So, a £10 bet at 5/1 would yield a profit of £50, making your total return £60 (including your initial stake).

2. Decimal Odds

Decimal odds, often used in mainland Europe, Australia, and Canada, represent the total amount you’ll get back for every unit staked – this includes your original stake. For example, odds of 6.00 mean that for every £1 you bet, you’ll receive £6 in return (your £1 stake plus £5 profit). The conversion from fractional to decimal is straightforward: simply divide the numerator by the denominator and add 1. Using our previous example, 5/1 as a decimal would be 6.00.

3. American (Moneyline) Odds

These odds are popular in the United States and come in two varieties: positive and negative. Positive figures, like +500, indicate how much profit you’d make on a $100 bet. In this case, a successful $100 bet would yield $500 profit. Negative figures, like -150, show how much you need to stake to make $100. So, you’d need to bet $150 to make a $100 profit.

3. Implied Probability

Every set of odds, regardless of format, implies a certain probability of an outcome occurring. This is crucial for bettors who want to find value in their bets. The implied probability is the reverse of odds; it tells you how often the bookmakers expect an outcome to happen.

Implied probability from fracional odds:

For fractional odds, the formula to calculate implied probability is:

Implied Probability=(Denominator)/(Denominator+Numerator)

For example, with odds of 5/1, the implied probability is 1/(5+1) = 1/6 = 16.67%. This means the event is expected to happen approximately 16.67% of the time.

Calculating Implied Probability from Decimal Odds:

To determine the implied probability from decimal odds, you’ll use the formula:

Implied Probability = 1 / Decimal Odds

For instance, if you have decimal odds of 3.00, the implied probability would be: Implied Probability = 1/3.00 = 0.3333

Calculating Implied Probability from American Odds:

The calculation for implied probability from American odds varies based on whether the odds are positive or negative:

For Positive American Odds (e.g., +200):

The formula is:

Implied Probability = 100/(American Odds+100)

For example, with American odds of +200: Implied Probability= 100/(200+100)=100/300=0.3333

This translates to a 33.33% chance of the event occurring.

For Negative American Odds (e.g., -150):

The formula is:

Implied Probability = American Odds/(American Odds-100)

Using American odds of -150 as an example:

Implied Probability = (−150)/(-150-100)=150/250=0.6

This means there’s a 60% chance of the event occurring, according to the odds.