9 in Roman Numerals
9 written in Roman numeralsIX
9 = IX. Read left to right: IX (9) = 9.
Going the other way, the Roman numeral IX equals the number 9.
How to write 9 in Roman numerals
- Ones: 9 is IX.
IX uses subtractive notation: IX means 9. A smaller symbol placed before a larger one is subtracted from it.
A common mistake is writing 9 as VIIII. Standard Roman numerals only allow I before V and X, X before L and C, and C before D and M, and no symbol repeats more than three times, so the correct form is IX.
9 is an odd number, a perfect square (3 × 3) and written with 2 symbols in Roman numerals.
Where you might see IX
- On a clock face, IX marks 9 o'clock.
- In dates written in Roman numerals, IX can stand for the month of September.
- Super Bowl IX was the 9th Super Bowl, played in early 1975.
- Book chapters, outlines, movie sequels and royal names use numerals like IX for the number 9.
Multiples of IX
| Sum | Number | Roman numeral |
|---|---|---|
| 9 × 2 | 18 | XVIII |
| 9 × 3 | 27 | XXVII |
| 9 × 5 | 45 | XLV |
| 9 × 10 | 90 | XC |
Numerals near IX
| Number | Roman numeral |
|---|---|
| 4 | IV |
| 5 | V |
| 6 | VI |
| 7 | VII |
| 8 | VIII |
| 9 | IX |
| 10 | X |
| 11 | XI |
| 12 | XII |
| 13 | XIII |
| 14 | XIV |
Questions
How do you write 9 in Roman numerals?
9 is written IX.
What number is IX?
IX is 9.