9 in Roman numerals
9 in Roman numerals
IX
9 is written IX in Roman numerals. That is 1 symbol group added together, reading left to right from the largest value down.
How it breaks down
| Group | Value | Subtraction | Running total |
|---|---|---|---|
| IX | 9 | X − I | 9 |
Why the smaller symbol comes first
IX uses subtractive notation in one place: IX means X minus I, or 9. A smaller symbol placed before a larger one is subtracted from it rather than added, which is why IX is nine and not eleven.
Only six such pairs are valid — IV, IX, XL, XC, CD and CM. That restriction is what makes the notation unambiguous: IIII and IC both look like they should work, but neither is standard, and only one spelling of any number is correct.
The symbols
| Symbol | Value | Used here |
|---|---|---|
| I | 1 | yes — 1× |
| V | 5 | no |
| X | 10 | yes — 1× |
| L | 50 | no |
| C | 100 | no |
| D | 500 | no |
| M | 1,000 | no |
The same number, other ways
- In words
- Nine
- Roman numeral
- IX
- Symbol count
- 2 characters
- Binary
- 1001
- Hexadecimal
- 9
The numbers either side
| Number | Roman numeral |
|---|---|
| 7 | VII |
| 8 | VIII |
| 9 | IX ← |
| 10 | X |
| 11 | XI |
Common questions
- What is 9 in Roman numerals?
- 9 is IX.
- What does IX mean?
- IX is the Roman numeral for 9 — 9.
- How do you write 9 in Roman numerals?
- Take the largest value that fits and repeat until nothing is left: IX (9). That gives IX.
Related pages
Sources
- Calculated on this page — At One Place