American to Fractional Odds Converter
Use this American to fractional odds converter to translate any moneyline price into the UK-style fractional format used in horse racing and British sportsbooks. American odds use signed numbers (+150, -200); fractional odds express the profit ratio as a fraction (3/2, 1/2).
The formula
Positive American (e.g. +150): Numerator ÷ Denominator = American ÷ 100. +150 → 150/100 → 3/2.Negative American (e.g. −200): Numerator ÷ Denominator = 100 ÷ |American|. −200 → 100/200 → 1/2.Even money: +100 = 1/1 ("evens"). -110 (standard US juice) ≈ 10/11.
Reference table
Common American (moneyline) lines and their fractional and implied probability values.
| American | Fractional | Probability |
|---|---|---|
| -500 | 1/5 | 83.3% |
| -200 | 1/2 | 66.7% |
| -149 | 67/100 | 59.9% |
| +100 | 1/1 | 50.0% |
| +150 | 3/2 | 40.0% |
| +200 | 2/1 | 33.3% |
| +300 | 3/1 | 25.0% |
| +400 | 4/1 | 20.0% |
| +500 | 5/1 | 16.7% |
| +900 | 9/1 | 10.0% |
Frequently Asked Questions
Why convert American to fractional?
UK and Irish bookmakers display odds in fractional form by default. If your model uses American moneyline (US default), convert before placing on a UK book like Bet365, William Hill, Coral, or Paddy Power.
Why does +100 equal 1/1?
+100 means winning $100 on a $100 stake: even money. 1/1 ("evens") means the same: 1 unit profit per 1 unit staked. Both are 50% implied probability.
What is -110 in fractional?
-110 is the standard US juice line (52.4% implied). The fractional equivalent is 10/11, a small favorite. The calculator above shows the exact reduction.
What about decimal or implied probability?
Use the full odds converter for all seven formats including decimal, implied probability, Indonesian, Hong Kong, and Malay.
Need a different format?
Open the full odds converter for decimal, implied probability, Indonesian, Hong Kong, and Malay.