Roman Numerals Reference
The seven letters that write numbers the Roman way, with the subtractive pairs and the values you actually meet in the wild.
At a glance
Key facts- Symbols
- I, V, X, L, C, D, M
- Subtractive
- IV, IX, XL, XC, CD, CM
- Repeats
- Three of a kind at most
- Still used
- Clocks, chapters, dates
Symbols and common values
15 rows| Numeral | Value |
|---|---|
| I | 1 |
| IV | 4 |
| V | 5 |
| IX | 9 |
| X | 10 |
| XL | 40 |
| L | 50 |
| XC | 90 |
| C | 100 |
| CD | 400 |
| D | 500 |
| CM | 900 |
| M | 1000 |
| MCMXCIV | 1994 |
| MMXXVI | 2026 |
Source: ISO 80000-2 and common typographic practice. This table has not been re-verified against the primary source; see the methodology for what that means and how to report a correction. 15 rows, dataset version 1.0.0. Changelog and JSON.
Where it comes from
Roman numerals grew out of tally marks in ancient Italy and were the everyday number system of the Roman world. The modern form uses seven letters: I, V, X, L, C, D, and M, combined by addition, with the later subtractive convention (IV for 4, IX for 9) becoming standard in the Middle Ages. The system survives today on clock faces, in book chapters and movie sequels, on monuments, and in the regnal numbers of monarchs and popes.
How to use it
Read left to right and add the values, except when a smaller symbol sits directly before a larger one, in which case you subtract it. Only six subtractive pairs are used: IV and IX, XL and XC, CD and CM. A symbol never repeats more than three times in a row, which is exactly why the subtractive pairs exist: 40 is XL, not XXXX. To decode a long numeral, split it into thousands, hundreds, tens, and units. MMXXVI is MM (2000), XX (20), VI (6), so 2026.
This page is a standing reference at a fixed URL, built to be linked and cited. The data here is compiled from the standard subtractive Roman numeral notation in modern use.