Fractional & decimal odds explained: reading 5/2, evens & 2.00

How fractional, decimal & moneyline odds express the same price, how to read returns from each, & what the starting price means in British racing.

Three formats, one price

Odds can be written in three main ways: fractional, decimal & moneyline. According to Wikipedia’s entry on fixed-odds betting, fractional odds are used primarily in the United Kingdom & Ireland, decimal odds are favoured in Continental Europe, Australia, New Zealand & Canada, & moneyline odds are used in the United States.

Moneyline odds, also called American odds, use a plus or minus sign followed by a number built around a $100 baseline. Fox Sports describes all three as different ways of showing a single price: “The same price can be shown three ways.”

Fox Sports also notes that “Most apps also let you switch to decimal or fractional odds in settings”, so the format a bettor sees is often a display choice rather than a different price.

Reading fractional odds such as 5/2

Fractional odds show the profit relative to the stake, the amount bet. Wikipedia gives the example of 4/1, read “four-to-one”, which means “a £400 profit on a £100 stake”.

The stake is returned on top of the profit. Wikipedia says “the bettor always receives his original stake back”, so a winning £100 bet at 4/1 returns £500 in total: £400 profit plus the original £100.

Great British Racing, describing the prices shown on boards in the betting ring, explains 5/2 this way: “for every 2 units you stake you receive 5 units back plus your initial stake”. The first number is the profit & the second is the stake needed to earn it.

Fox Sports gives a similar example: “Odds of 3/2 mean you win $3 for every $2 bet.” Wikipedia adds that the term “fractional odds” is something of a misnomer, because the fraction does not represent the chance of winning, only the profit as a share of the stake. Fractional odds are also known as British, UK or traditional odds.

Evens & odds-on prices

Great British Racing says “EVENS is the equivalent of a 1/1 fraction”. The Jockey Club explains that evens means “a profit of £1 for every £1” bet, & that in decimal odds it is “displayed as 2.00”.

An odds-on price is one where a horse is a strong favourite. The Jockey Club says this means “a profit of less than £1 for every £1”, that in fractions “the larger number is on the bottom of the fraction i.e. 1/2”, & that in decimals it shows as “a number less than 2.00”.

Great British Racing describes 1/2 as “for every 2 units you stake you will receive 1 unit back plus your initial stake”. Wikipedia says 1/4, read “one-to-four” or “four-to-one on”, means the bettor “stands to make £25 on a £100 stake”.

At the other end of the scale, The Jockey Club describes 50/1 as long odds, meaning a horse is expected to have a low chance of winning, & 6/4 as short odds, meaning a high expected chance & a relatively small profit.

Reading decimal odds

Decimal odds show the total return for each unit staked, with the stake already included. Sporting Life says that “As the unit stake is always included, decimal odds always have a value greater than 1.”

Sporting Life’s example is a £1 stake at 6.0, which returns £6 in total, made up of £5 winnings & the £1 stake. That is the same outcome as a £1 bet at 5/1.

Great British Racing says to “multiply your stake by the number shown”, so £2 at 5.00 comes to 10, adding that “your stake is already factored in when using decimal odds”. Fox Sports gives a dollar example: “Odds of 2.50 mean a $10 bet returns $25”, which is $15 profit.

Sporting Life notes that odds-on selections appear as values between 1.0 & 2.0 in decimal form. Its coin-toss example prices a bet at 1.98, so a successful £1 stake returns £1.98, a profit of 98p.

Decimal equals fraction plus one

Wikipedia states that decimal odds are “equivalent to one plus the decimal value of the fractional odds”. The extra one is the returned stake.

On that basis, Wikipedia says “even odds 1/1 are quoted in decimal odds as 2”, 4/1 is quoted as 5 & 1/4 as 1.25.

Converting the other way can produce awkward fractions. Sporting Life points out that “where the decimal odds are 1.46, the fractional equivalent would be 23/50”, & argues it is much easier to calculate the return from a £1 stake using the decimal figure.

Sporting Life also notes that fractions can confuse beginners when decimal odds fall below 2, because the second number becomes larger than the first, so 2/1 & 1/2 can look alike at a glance.

A quick conversion table

Fox Sports publishes a conversion table linking the three formats with implied probability, which it describes as turning “the odds into the percentage chance the price suggests”.

In that table, 1/2 equals 1.50 in decimal & -200 in American odds, an implied probability of 66.7%. 2/3 equals 1.67 & -150 (60.0%), & 10/11 equals 1.91 & -110 (52.4%).

Evens (1/1) equals 2.00 & +100 (50.0%). 3/2 equals 2.50 & +150 (40.0%), 2/1 equals 3.00 & +200 (33.3%), & 5/1 equals 6.00 & +500 (16.7%).

Implied probabilities include the bookmaker’s margin. Wikipedia explains that bookmakers aim for an overround, where “the sum of probabilities quoted for all possible outcomes exceeds 100%”, & that the excess represents profit to the bookmaker in a balanced book.

Fox Sports gives an example: two sides both priced at -110 add up to 104.8%, not 100%, & it calls the extra “the vig, the sportsbook’s margin”.

Where each format is used

Fractions remain the traditional format in British & Irish racing. Great British Racing says “In the betting ring the odds are most commonly displayed in their traditional fractional form”, & Fox Sports describes fractional odds as traditional in the UK & Ireland, “especially for horse racing”.

Decimals dominate elsewhere. Sporting Life says “Many betting websites – including the Betfair Exchange – now use decimal odds as standard” & that “decimal odds are commonly used all over Europe”. Wikipedia says decimal odds “tend to be used by betting exchanges” because they are the easiest to work with for trading.

Decimals also simplify multiples, bets that combine several selections, called parlays in the US. Wikipedia says the payout is “simply the product of the odds for each outcome wagered on”.

Fox Sports gives a worked case: two selections at -110 convert to 1.91 x 1.91, so a $10 two-leg parlay returns about $36.45.

Starting price (SP)

The Jockey Club defines the starting price, or SP, as “the official odds a horse started the race with”. Wikipedia describes starting prices as “wagers whose price is determined only when the race or game starts”.

This differs from a fixed-odds bet, which The Jockey Club says gets “the odds advertised by the betting operator at the time you placed the bet”. It adds that “You can ask to place an SP bet with a bookmaker (but not the Tote)”.

The Starting Price Regulatory Commission (SPRC) is, in the words of the Racing Post, “the body responsible for the integrity and accuracy of the SP”. The Racing Post reported that the on-course market was the exclusive source for the SP until racing went behind closed doors in June 2020, & that in March 2021 the SPRC decided the SP would be formulated using off-course firms.

Under the updated rules the Racing Post described, a price source counts if it is freely available to customers in the UK, offers each-way terms derived from the win-only price, & makes up at least 1% of the UK market for betting on British racing. The Racing Post reported that the each-way condition rules out the Betfair exchange & the Tote.

At the time of that report, the SPRC said the bookmaker brands providing the SP sample were bet365, Betfred, Ladbrokes, Paddy Power, Sky Bet, Unibet & William Hill.

Questions

What does 5/2 mean in betting?

Great British Racing explains that at 5/2, “for every 2 units you stake you receive 5 units back plus your initial stake”.

What does evens mean?

Evens is the equivalent of 1/1, a profit of £1 for every £1 bet. The Jockey Club says it is displayed as 2.00 in decimal odds.

What does odds-on mean?

According to The Jockey Club, an odds-on price makes a profit of less than £1 for every £1 bet. It has the larger number on the bottom of the fraction, such as 1/2, & shows as less than 2.00 in decimal odds.

How do you convert fractional odds to decimal?

Wikipedia says decimal odds equal one plus the decimal value of the fractional odds. On that basis, 4/1 becomes 5, 1/4 becomes 1.25 & evens becomes 2.

Can you take the starting price on any bet?

The Jockey Club says you can ask to place an SP bet with a bookmaker, but not the Tote.

Sources

• en.wikipedia.org
• greatbritishracing.com
• thejockeyclub.co.uk
• sportinglife.com
• foxsports.com
• racingpost.com

Sources checked 29 October 2026. Information only. 18+.