Roman numeral converter
Convert a number into Roman numerals, or decode a Roman numeral back into a number. Works for 1 to 3999.
Roman numeral
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How Roman numerals work
Seven letters carry fixed values: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. Symbols are written largest-first and added together, except for six subtractive pairs — IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900) — where a smaller letter before a larger one is subtracted. Standard notation tops out at 3999 (MMMCMXCIX); larger numbers need an overline, which plain text can't show.
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |