9 in Roman numerals

9 = IX

Working: IX = 9

The number 9 is written as IX in Roman numerals.

Roman numerals are built by adding symbol values together from largest to smallest: IX = 9. Where a smaller symbol appears before a larger one — as in IV for 4 or IX for 9 — it is subtracted rather than added, which keeps the notation short.

Structurally, IX is 2 symbols long. It uses the subtractive pair and IX, which must be read as a unit rather than symbol by symbol. No symbol repeats.

IX is the second subtractive numeral: one before ten rather than five plus four, which would give the disallowed VIIII. It is the shortest possible way to write nine and a good illustration of what the subtractive rule is for — brevity, not elegance.

Nearby numbers

Number	Roman numeral
4	IV
5	V
6	VI
7	VII
8	VIII
10	X
11	XI
12	XII

Try another value

Decimal number (1–3999)

Roman numeral

MMXXIV

Reference

X10

L50

C100

D500

M1000

Frequently asked questions

How do you write 9 in Roman numerals?

9 is written IX. It breaks down as IX = 9.

What are the seven Roman numeral symbols?

I is 1, V is 5, X is 10, L is 50, C is 100, D is 500, and M is 1,000. All Roman numerals are combinations of these seven symbols, and there is no symbol for zero.

For any other value, use the full Roman Numeral Converter on BrainVert.