Number
9 in Roman numerals
9 is written IX
Type any other number or numeral below to convert it.
Above 3,999? Type the barred part in brackets, e.g. (IV)CC = 4,200.
How IX is built
Roman numerals are written one decimal place at a time, largest first.
- IXones · 9I before X means 10 − 1 = 9. This saves writing VIIII.
The pair IX uses subtraction: a smaller letter before a larger one is taken away from it. Only six pairs work this way: IV, IX, XL, XC, CD and CM. More on subtraction
Mistakes to avoid
- Not VIIII (5 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today IX (2 letters) is the standard.
About the number 9
- 9 is odd and a square number: 3 × 3, or in Roman numerals III × III.
- IX has 2 letters. 969 of the numbers up to 1,000 have longer numerals.
- On a clock face, 9 o'clock is IX.
- As a month in a date, IX is September.
- As a day of the month, IX is the 9th. Write a date
Counting from 1 to 10
| Number | Roman numeral |
|---|---|
| 1 | I |
| 2 | II |
| 3 | III |
| 4 | IV |
| 5 | V |
| 6 | VI |
| 7 | VII |
| 8 | VIII |
| 9 | IX |
| 10 | X |