American odds and fractional odds rarely appear side by side — American is the U.S. moneyline default, while fractional is the UK and Irish racing default. To convert, the easiest path is via decimal: turn the American odds into decimal, then express the decimal-minus-1 part as a fraction.
Quick example: +150 (American) = 3/2 (fractional). Use the calculator below for any value, or scroll for the full conversion table.
Convert through decimal:
Fraction = American / 100, simplifiedFraction = 100 / |American|, simplifiedCommon odds across all three formats. Use this as a quick reference; the calculator above handles any value to four decimal places of precision.
| Decimal | American | Fractional |
|---|---|---|
| 1.10 | -1000 | 1/10 |
| 1.25 | -400 | 1/4 |
| 1.40 | -250 | 2/5 |
| 1.50 | -200 | 1/2 |
| 1.67 | -150 | 4/6 |
| 1.75 | -133 | 3/4 |
| 1.83 | -120 | 5/6 |
| 1.91 | -110 | 10/11 |
| 2.00 | +100 | 1/1 (Evens) |
| 2.10 | +110 | 11/10 |
| 2.25 | +125 | 5/4 |
| 2.50 | +150 | 6/4 |
| 3.00 | +200 | 2/1 |
| 3.50 | +250 | 5/2 |
| 4.00 | +300 | 3/1 |
| 5.00 | +400 | 4/1 |
| 6.00 | +500 | 5/1 |
| 11.00 | +1000 | 10/1 |
| 21.00 | +2000 | 20/1 |
| 51.00 | +5000 | 50/1 |
| 101.00 | +10000 | 100/1 |
American odds appear on every U.S. sportsbook display, U.S. sports broadcasts, and U.S. betting media. They are the working language of moneyline, point-spread "juice", and prop pricing in the United States.
Fractional odds are the British and Irish standard — Cheltenham, Royal Ascot, the Grand National, and the high-street bookies all post prices in fractions. Any time a UK or Irish friend or article quotes you a price, expect a fraction.
+100 = 1/1, called "Evens". A £10 bet returns £20 total (£10 profit).
−110 ≈ 10/11 (an odds-on favorite). You risk £11 to win £10. The implied probability is about 52.4% — the standard "juice" at U.S. books.
Both are mathematically identical. Most operators simplify to the smallest whole-number form, so 2/1 is far more common than 6/3.
−500 American = 1/5 fractional (decimal 1.20). −1000 American = 1/10 fractional (decimal 1.10). The fraction inverts ("odds-on") for any decimal under 2.00.