Roman Numeral Converter
Convert between Roman numerals and decimal numbers (1-3999) instantly.
Type in either field and the other updates automatically.
Type in either field — the other updates instantly. Supports numbers 1–3999.
Roman numerals use letters to represent values.
Basic symbols:
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Rules:
- Symbols are generally written largest to smallest, left to right.
- When a smaller symbol appears before a larger one, it is subtracted.
- I before V or X = 4 (IV) or 9 (IX)
- X before L or C = 40 (XL) or 90 (XC)
- C before D or M = 400 (CD) or 900 (CM)
Examples:
- 2024 = MMXXIV
- 1999 = MCMXCIX
- 42 = XLII
- 3999 = MMMCMXCIX (largest standard Roman numeral)