how do betting odds work

Free Decimal/Fractional Odds Converter

When it comes to how the betting odds work on a sports wager, fractional odds, or British or UK odds as they’re known due their popularity with British and Irish online bookmakers, as well as in the sport of horse racing, are perhaps the easiest to understand.

Here is your free fractional to decimal odds betting converter by Spreadex. Understand how odds work, calculate probabilities before placing your bet online.

Fractional to decimal odds converter

How To Calculate Decimal And Fractional Odds

The numbers in a fractional odds listing will be divided by either a slash or a dash. Thus, you might see the odds listed as 11/1, or perhaps 18-1. A fractional listing of 10/1 (ten-to-one) odds would indicate that a bettor would win £10 for every £1 they wagered, in addition to receiving your dollar back. That’s the amount of the wager, also known as the stake. In essence, it is the ratio of the amount won against the initial bet. So the stake (£1) is returned with a successful punt, as well as the amount earned on the wager. At 10/1, that profit margin would be £10.

In the case of decimal odds, the decimal odds number is representative of the amount a bettor wins for every £1 wagered. In a decimal odds calculation, the number represents the total payout, rather than the profit. With decimal odds, the amount of the stake is already folded into the decimal number. It’s not necessary to go back and add the stake to the profit. It’s all packaged into one handy digit, making it far easier and quicker to calculate the amount of the total payment in decimal odds. As an example, if Stoke City were listed at 4.00 odds in a match against Queen’s Park Rangers, a £100 punt on Stoke would return £400 if City won the match. To calculate a decimal odds payout, simply multiply the stake wagered by the decimal odds number.

What are the odds?

The odds offer a reflection of the sportsbook’s oddsmaker’s assessment of the probability of a bet coming to fruition. Fractional odds are taking into account the return on investment from a successful wager. If a punter were to lay a bet of £20 at odds of 5/1 for instance, the wager would garner the player £100. As well, the original £20 stake would be returned to the bettor. So the total returned is £120. Try 10bet or Betfred.

How to calculate the probability of odds?

The simplest way to calculate the probability of a fractional betting odds wager coming in is to take the two numbers in the odds, add them together and then divide the No. 1 with them. For instance, on a 7-1 wager, add the digits together to get eight. Then divide one by eight. This will determine that a 7-1 wager has a .125 chance of being a winner. 

In order to calculate the winnings with decimal odds, you must multiply the skate by the decimal odds number. Thus, if Leicester City were at 1.3 and Newcastle United were at 4.00, favoured Leicester would pay out £6.50 on a £5 wager (5×1.3=6.50). However, if the same £5 were wagered on Newcastle and they won the match, the return would be £20 (5×4=20). 

Football Odds

Let’s suppose Liverpool is playing host to Aston Villa and Anfield. Hometown Liverpool are 1-5 favorites. Aston Villa is a 5-1 away underdog with bet365 offers.

At those odds, punters who back Liverpool would have an 83.3 percent chance of cashing a winning ticket. On the other hand, backers of Aston Villa would be left with just a 16.6 percent chance of a successful punt.

Soccer Betting Odds at bet365 UK
Soccer Betting Odds at bet365 UK

Cricket Odds

Beyond the straight bet on which team will be the match winner, cricket odds are offered by online betting sites like Betfred Sports in a variety of markets. These can include such variants as who will score the most runs, which player will take most wickets, and who will be named the man of the match.

Cricket Betting Odds Example
Cricket Betting Odds Example

Rugby Odds

Rugby offers betting odds on the match winner, but will also offer point spreads that give a bit better odds on favourites, since they must win the match by a specific margin. There’s also over/under wagering on total points scored in the match with 888Sport or Boylesports.

Tennis Odds

On the surface, the tennis odds might look similar to the odds for other sports. Yes, there are straight odds on the match winner (during Wimbledon, for example). But in tennis, spread betting covers the margin of games won between the two players. And the total is factoring in the number of games that will be required to complete the match. Set betting markets are also offered by a range of UK betting apps, such as Unibet and William Hill.

The Difference Between Decimal And Fractional Odds 

Decimal and fractional odds are the two most common forms of odds calculations utilized by online sports betting sites in the UK and Europe. Also known as British odds, or traditional odds, fractional odds are the ratio of the amount (profit) won to the stake.

Fractional odds (aka British odds, UK odds, or traditional odds) are popular among British and Irish bookies. The first choice in terms of the method of displaying the odds on a sporting event, fractional odds are utilized by many of the most prominent bookmakers around. That also makes them the most preferred odds among the leading online betting sites.

In the case of decimal odds, also referred to as European odds, they represent the amount a punter wins for every  £1 wagered.  Decimal odds are the betting odds of choice in Canada, Australia, New Zealand and continental Europe.

3 UK Bookies With the Best Odds

Converting American To Decimal Odds

In sports betting, there are three main types of odds that are employed by online sports betting sites in order to calculate wagering outcomes.

In the United Kingdom and Ireland, fractional odds are the most common form of betting calculation. For instance, a horse might be listed at 2/1 to win a race at Ascot. With fractional odds, the numbers represent the ratio of the amount of payout, or profit, that a successful wager will return to a punter, based on every £1 wagered. In this instance, at 2/1, a £1 bet would realize a £2 return. A £10 bet would return £20 to the punter.

The other common forms of calculating the odds are known as American odds, since this format is most popular in the USA and decimal odds, which are prevalent in countries such as Canada, Australia, New Zealand and most of continental Europe.

Explaining American Odds

American odds employ a positive and negative format to calculate the odds based on wagers of £100. Favourites are assigned negative numbers, while positive numbers are attached to betting underdogs.

Suppose Manchester United were -175 facing Brighton & Hove Albion at +300. In this example, Brighton is the underdog. The +300 odds mean that if they were to win the match and you’d wagered £100 on them, you would realize a profit of £300.

In the case of favoured Manchester United, the -175 represents how much of a stake must be laid in order to realize a £100 profit on a successful punt. 

American Odds Example
American Odds Example

Converting American To Decimal Odds

In order to make a conversion from American to decimal odds, the formula depends upon whether the number in question is positive or negative.

To convert a positive number, such as the +300 in the above example on Brighton, you would divide the odds by 100 and add one. Thus, it’s 300/100+1=4.00. To change over a negative number like the -175 on Manchester United, the formula is to divide 100 by the odds and add one. In this case, that’s 100/-175+1=1.57.