What 100/30 means
With fractional odds, the first number is what you win and the second is what you stake. At 100/30, every £30 you stake wins £100 in profit, and your stake is returned on top. Because you win more than you stake, it's an odds-against price: the bookmaker rates this outcome as less likely to happen than not.
It's read as "a hundred to thirty".
100/30 is the traditional way of writing 10/3, and the two are exactly the same price. Bookmakers have quoted it this way for generations, along with 85/40 and 95/40.
100/30 in decimal and American odds
| Format | 100/30 as | How it's worked out |
|---|---|---|
| Decimal | 4.33 | 100 ÷ 30 + 1 |
| American | +333.33 | (4.33 − 1) × 100 |
| Implied probability | 23.1% | 1 ÷ 4.33 |
What 100/30 pays
| Stake | Profit | Total return |
|---|---|---|
| £1.00 | £3.33 | £4.33 |
| £2.00 | £6.67 | £8.67 |
| £5.00 | £16.67 | £21.67 |
| £10.00 | £33.33 | £43.33 |
| £20.00 | £66.67 | £86.67 |
| £50.00 | £166.67 | £216.67 |
| £100.00 | £333.33 | £433.33 |
How likely is 100/30 to win?
100/30 implies a 23.1% chance, or about 3 in 13. In other words, the bookmaker expects it to win roughly three times for every thirteen attempts. The true chance is usually a little lower than this, because bookmakers build a margin into every price.
100/30 each way
An each way bet splits your stake between a win bet and a place bet, with the place part paid at a fraction of 100/30. For a £5 each way bet (£10 in total):
| Place terms | Place odds | Returns if it wins | Returns if it places |
|---|---|---|---|
| 1/4 odds | 5/6 | £30.83 | £9.17 |
| 1/5 odds | 2/3 | £30.00 | £8.33 |
At 1/5 terms, a placed finish returns £8.33 from the £10 total stake, so it still loses £1.67 overall. Each way needs bigger prices than 100/30 for the place part to cover the bet. Work out any each way bet.
If a horse at 100/30 is withdrawn
When a horse priced at 100/30 is withdrawn after you've bet on another runner in the same race, Rule 4 takes 20p from every £1 of your winnings. It applies to bets struck at a fixed price before the withdrawal. Work out a Rule 4 deduction.
Prices either side of 100/30
See every common price explained, or convert any price with the odds converter.