1. Fractional Percentage Calculator
2. Fractional Odds To Percentage Calculator
3. Fractional Odds To Percentage Increase

Calculator Use

Convert stated odds to a decimal value of probability and a percentage value of winning and losing. This calculator will convert 'odds for winning' an event or 'odds against winning' an event into percentage chances of both winning and losing.

Be careful if you are using sports teams odds or betting odds. If you see that the Patriots super bowl odds are 9/2, that is most likely 'odds against' and should be entered in the calculator with 'Odds are: against winning.'

• For example, 'Decimal Odds' of 3.00 has an implied probability of 33.3% which can then be converted to fractional odds of 2/1. This article discusses this process of odds conversion in detail with the use of step by step real world examples.
• High odds suggest a low probability of something happening, while low odds suggest a high probability of something happening. For example, imagine a tennis player is +200 to win an upcoming match. This would be 3.00 in decimal odds, and 2/1 in fractional odds. The implied probability for these odds.
• (1) Dividing the left-hand side of the fraction by the right-hand side, e.g. Fractional odds of 7/4 would be 7 divided by 4 which equals 1.75 (2) Add 1 to the result e.g. 1.75 + 1 gives decimal odds of 2.75 Fractional odds can make it a little tricky when trying to work out your return and profit.
• This most likely means '500 to 1 Odds are against winning' which is exactly the same as '1 to 500 Odds are for winning.' Probability Formulas: This calculator will convert 'odds of winning' for an event into a probability percentage chance of success. Odds, are given as (chances for success): (chances against success) or vice versa.

When playing a lottery or other games of chance be sure you understand the odds or probability that is reported by the game organizer. A 1 in 500 chance of winning, or probability of winning, is entered into this calculator as '1 to 500 Odds are for winning'. You may also see odds reported simply as chance of winning as 500:1. This most likely means '500 to 1 Odds are against winning' which is exactly the same as '1 to 500 Odds are for winning.'

Probability Formulas:

This calculator will convert 'odds of winning' for an event into a probability percentage chance of success.

Odds, are given as (chances for success) : (chances against success) or vice versa.

For example, a bet placed at +200 in American odds (2/1 in fractional or 3.00 in decimal) has a 33.33 percent implied winning probability. A bet placed at -200 in American odds (1/2 in fractional.

If odds are stated as an A to B chance of winning then the probability of winning is given as P_W = A / (A + B) while the probability of losing is given as P_L = B / (A + B).

For example, you win a game if you pull an ace out of a full deck of 52 cards. Pulling any other card you lose. The chance of winning is 4 out of 52, while the chance against winning is 48 out of 52 (52-4=48). Entering A=4 and B=48 into the calculator as 4:48 odds are for winning you get

For 4 to 48 odds for winning;
Probability of:
Winning = (0.0769) or 7.6923%
Losing = (0.9231) or 92.3077%
'Odds for' winning: 1:12 (reduced from 4:48)
'Odds against' winning: 12:1 (reduced from 48:4)

Further Reading

Fractional odds, also known as UK Odds are most often used in the United Kingdom and Ireland. Originally used in horse racing, fractional odds are one of the oldest forms of odds for sports gamblers. If you were to walk down London’s high street of bookmakers, you would see fractional odds adorning the walls of some the largest bookies in the world.

Fractional odds are extremely simple to calculate because well, they are given in fraction form. The denominator or 2nd number to the right is the amount bet and the numerator or 1st number on the left is the amount that your wager will yield. Let’s say you wager on Liverpool at 10 to 15 fractional odds. For every $150 wagered, your potential net profit would be $100. If you win, your original stake will also be returned to you, leaving you with $250 ($150 original wager + $100 profit) and a net of result of plus $100.

Liverpool 10/15: $150 to win $100 = $250

Let’s look at wagering on an underdog or high odds bet, where the odds are more in your favor. Say you join a new betting site and are placing a wager Newcastle United, the underdog at five-to-one fractional odds, if you were to bet $100 your potential return would be $600, a $500 profit and your original bet of $100 would be returned to you.

Newcastle United: 5/1: $100 to win $500 = $600

If you are wagering on an event where there is a definitive favorite and underdog, the odds of the favorite is often referred to as the “odds on” and the odds of the underdog as the “odds against.” If a bet is even money, the odds are not one-to-one due to the bookmaker’s juice or commission. In most cases, the odds will be 10 to 11, where the bettor risks $110 to win $100.

Fractional Percentage Calculator

Fractional odds can also be attached to a point spread:

New York Giants -7 10/11
Philadelphia Eagles +7 10/11

The juice or commission on each bet here is fractional odds of 10 to 11, so you would need to wager 110 to win 100.

Converting Fractional Odds to Decimal Odds:

An easy way to convert fractional odds to decimal odds is to convert the fraction into decimal form and then add a 1. For example, 5/1 or five-to-one fractional odds would be 6.00 in decimal odds.

5 / 1 = 5+1 = 6.00

Here is a conversion when you are wagering on a large favorite:

1 / 5 = 0.2+1 = 1.2

Conclusion

Understanding fractional odds is especially important to UK bettors, but even those not normally using these odds can benefit from understanding them. Used by the world’s largest bookmakers, there is no doubt fractional odds are one of the preferred odds for sports bettors across the world.

Fractional Odds To Percentage Calculator

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Fractional Odds To Percentage Increase