How Roman numerals work
Roman numerals use combinations of seven letters: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numerals are generally written largest to smallest, with subtractive notation used for four and nine patterns (like IV for 4, IX for 9, XL for 40) instead of repeating a symbol four times.
Symbol reference table
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | C | 100 |
| V | 5 | D | 500 |
| X | 10 | M | 1000 |
| L | 50 |
Frequently asked questions
What's the largest number this converts? Standard Roman numerals go up to 3,999 (MMMCMXCIX) — beyond that, ancient notation used a bar over letters to multiply by 1,000, which isn't standard on modern keyboards.
Where are Roman numerals still used today? Clock faces, movie copyright years, book chapters, Super Bowl numbering, and monarch/pope names (like Elizabeth II) are common modern uses.