Definition
Fractional Odds
Also known as British Odds, Traditional Odds, UK Odds
By Abhinav VasudevanReviewed Editorial policy
In short
Fractional odds show profit relative to stake. 5/1 means five units of profit for every one staked; 5/2 means five profit for every two staked. Your stake is returned separately on top.
Fractional odds are the traditional British format, still standard in horse and greyhound racing and still what you will hear shouted in a betting ring. They express profit to stake, which is the source of most confusion about them.
Reading them
The left number is what you win; the right is what you stake.
- 5/1 (“five to one”). £5 profit per £1 staked. A £10 bet returns £60.
- 5/2 (“five to two”). £5 profit per £2 staked. A £10 bet returns £35.
- 1/2 (“two to one on”). £1 profit per £2 staked. A £10 bet returns £15.
Total return = stake + (stake × numerator ÷ denominator)
The stake is always returned on top of the profit. This is the key difference from decimal odds, where the stake is already inside the quoted number: 5/1 and 6.00 are the same price.
Odds-on and odds-against
When the left number is larger, the selection is odds-against. You win more than you risk.
When the right number is larger, it is odds-on. You risk more than you win. Racing convention reverses the spoken order: 1/2 is said “two to one on”, not “one to two”.
Evens (written 1/1 or EVS) is the pivot: £10 wins £10, returning £20.
The awkward fractions
Bookmakers price to a traditional ladder rather than to arbitrary fractions, which is why you see 11/8, 15/8, 6/4 and 100/30 rather than tidy numbers.
A few that catch people out:
| Fraction | Decimal | Implied |
|---|---|---|
| 6/4 | 2.50 | 40.0% |
| 11/8 | 2.375 | 42.1% |
| 15/8 | 2.875 | 34.8% |
| 100/30 (“hundred to thirty”) | 4.33 | 23.1% |
| 5/4 | 2.25 | 44.4% |
100/30 is a genuine historical survival, equivalent to 10/3, and still quoted at British racecourses.
Why it persists, and why it is worse
Fractional odds are harder to compare, harder to convert and harder to multiply. Deciding quickly whether 11/8 is better than 7/5 requires arithmetic that decimal makes trivial. They are 2.375 and 2.40, so 7/5 is better, but almost nobody sees that at a glance.
The format survives on tradition and on the rhythm of racecourse betting. If you are comparing prices seriously, switch your account display to decimal. The bet is identical; only your ability to evaluate it changes.
Common questions
How do I read fractional odds?
The left number is profit, the right is your stake. 5/1 pays £5 profit per £1 staked, and 5/2 pays £5 per £2. Your stake always comes back on top, so £10 at 5/2 returns £35 in total.
What does odds-on mean in fractional odds?
The right number is larger than the left, so you risk more than you win. Racing reverses the spoken order, meaning 1/2 is said as two to one on rather than one to two. It implies a probability above 50%.
Why does racing still use fractions?
Tradition and the rhythm of racecourse betting. They are harder to compare, convert and multiply than decimals, and most operators let you switch the display in account settings. Switching is the easiest improvement most bettors can make.