What 100/1 means
With fractional odds, the first number is what you win and the second is what you stake. At 100/1, every £1 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 one".
100/1 in decimal and American odds
| Format | 100/1 as | How it's worked out |
|---|---|---|
| Decimal | 101.00 | 100 ÷ 1 + 1 |
| American | +10000 | (101.00 − 1) × 100 |
| Implied probability | 1.0% | 1 ÷ 101.00 |
What 100/1 pays
| Stake | Profit | Total return |
|---|---|---|
| £1.00 | £100.00 | £101.00 |
| £2.00 | £200.00 | £202.00 |
| £5.00 | £500.00 | £505.00 |
| £10.00 | £1,000.00 | £1,010.00 |
| £20.00 | £2,000.00 | £2,020.00 |
| £50.00 | £5,000.00 | £5,050.00 |
| £100.00 | £10,000.00 | £10,100.00 |
How likely is 100/1 to win?
100/1 implies a 1.0% chance, or about 1 in 101. In other words, the bookmaker expects it to win about once in every 101 attempts. The true chance is usually a little lower than this, because bookmakers build a margin into every price.
100/1 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 100/1. For a £5 each way bet (£10 in total):
| Place terms | Place odds | Returns if it wins | Returns if it places |
|---|---|---|---|
| 1/4 odds | 25/1 | £635.00 | £130.00 |
| 1/5 odds | 20/1 | £610.00 | £105.00 |
At 1/5 terms, a placed finish alone returns £105.00 from the £10 total stake, so the place part covers the whole bet with £95.00 to spare. Work out any each way bet.
If a horse at 100/1 is withdrawn
A horse priced at 100/1 being withdrawn doesn't trigger a Rule 4 deduction. The scale only applies when the non-runner was 14/1 or shorter. Work out a Rule 4 deduction.
Prices either side of 100/1
| Price | Decimal | Implied probability |
|---|---|---|
| 80/1 | 81.00 | 1.2% |
| 100/1 | 101.00 | 1.0% |
| 125/1 | 126.00 | 0.8% |
See every common price explained, or convert any price with the odds converter.