IX is a single Roman symbol group for 9. It uses subtractive notation: IX (10 - 1).
How 9 is written in Roman numerals
The number 9 is written IX in Roman numerals. Roman numerals use seven letters — I (1), V (5), X (10), L (50), C (100), D (500) and M (1000) — combined from largest to smallest, with subtractive pairs such as IV (4) and IX (9). Need another number? Use the Roman numeral converter or see the 1–100 chart.
Building IX step by step — take the largest value that fits, write its symbol, subtract, repeat.
| Write | Value | Remaining before | Remaining after |
|---|
| IX | 9 | 9 | 0 |
Where you see IX
On a clock face, the 9th hour is marked IX. Regnal and papal names use it the same way — a 9th ruler of a name is styled IX, as in Louis IX or Pope John IX. The 9th Super Bowl was Super Bowl IX; the NFL has used Roman numerals for every edition except Super Bowl 50.
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Frequently Asked Questions
What is 9 in Roman numerals?
9 in Roman numerals is IX. It is written as one value group, IX, worth 9 on its own, so nothing has to be added to it. The number below it, 8, is written VIII, and the number above it, 10, is written X.
How do you write 9 in Roman numerals?
Write 9 as IX, a single Roman symbol group worth 9. Roman numerals are built by taking the largest value that still fits, writing its symbol and subtracting it, which reduces 9 in 1 step: IX leaves 0. Every symbol keeps the same value wherever it stands, so the order is fixed and IX is the only standard spelling of 9.
Does IX use subtractive notation?
Yes, IX uses subtractive notation. Here IX means 10 minus 1. Without it, 9 would have to be written VIIII, and Roman numerals avoid a run of four identical letters wherever a subtractive pair will do.
What is 9 times ten in Roman numerals?
9 times ten is 90, which is XC in Roman numerals, not IX with a letter added on the end. Roman numerals have no place value, so multiplying by ten respells the whole numeral instead of shifting digits along. Compare IX for 9 with XC for 90.