Roman Numeral Converter
Convert between Roman numerals and Arabic numbers. Supports numbers from 1 to 3999 with conversion rules explained.
Roman Numeral
MMXXV
Roman Numeral Reference
| Roman | Value | Roman | Value |
|---|---|---|---|
| I | 1 | V | 5 |
| X | 10 | L | 50 |
| C | 100 | D | 500 |
| M | 1000 | IV | 4 |
| IX | 9 | XL | 40 |
| XC | 90 | CD | 400 |
| CM | 900 |
Supports numbers from 1 to 3,999. A smaller numeral before a larger one means subtraction (e.g., IV = 4, IX = 9).
About Roman Numerals
Roman numerals originated in ancient Rome and use combinations of letters (I, V, X, L, C, D, M) to represent numbers. They are still widely used today for clock faces, book chapters, movie sequels, Super Bowl numbering, and formal documents. This converter handles numbers from 1 to 3,999 (the standard range of Roman numerals).
How to Use This Converter
- Choose "Number to Roman" or "Roman to Number" mode
- Enter a number (1-3999) or type a Roman numeral
- See the instant conversion with a reference table below
Subtractive Notation Rules
Roman numerals use subtractive notation for certain values: IV = 4 (5 - 1), IX = 9 (10 - 1), XL = 40 (50 - 10), XC = 90 (100 - 10), CD = 400 (500 - 100), and CM = 900 (1000 - 100). A smaller numeral placed before a larger one means you subtract the smaller from the larger value.