Odds are just a way of expressing two things at once: how much a bet pays and how likely the outcome is judged to be. The confusing part for many bettors is that the same price can be written in more than one format. Decimal and fractional odds are the two you will meet most often.
The good news is that they are perfectly interchangeable. A price is a price; the format is only the language it is written in. Learn to read both and to convert between them, and you will never be thrown by a bookmaker's display again.
Fractional Odds
Fractional odds, such as 5/1 or 7/2, are traditional in UK racing. The left number is the profit and the right number is the stake it relates to. So 5/1 means five units of profit for every one staked, plus your stake back. 7/2 means three and a half units of profit per unit staked.
Reading Fractions Quickly
Divide the left number by the right to get the profit per unit. 7/2 becomes 3.5, meaning a £2 stake returns £7 profit plus the £2 stake. Fractions with a larger right-hand number, like 4/5, are odds-on, where you stake more than you stand to win.
Decimal Odds
Decimal odds, such as 6.00 or 4.50, show your total return per unit staked, including your stake. 6.00 means a £1 stake returns £6 in total: £5 profit plus your £1 back. Many bettors prefer decimals because the maths is simply stake times odds.
Converting Between the Two
- Fractional to decimal: divide the fraction and add 1. 5/1 becomes 5 + 1 = 6.00.
- Decimal to fractional: subtract 1 and express as a fraction. 4.50 becomes 3.5, or 7/2.
Because the two are just different notations for the same price, your return is identical whichever you use. If you want to see this in practice, enter the same bet in both formats in the Bet Calculator Betmentor and confirm the returns match.
Which Format Should You Use?
Use whichever your bookmaker shows and whichever you find easier to read. Decimals make accumulator maths cleaner because you multiply the numbers directly. Fractions remain the norm for UK racing. Being fluent in both is the real goal, and it feeds naturally into understanding implied probability.