Roman Numeral Converter
Convert between Arabic numbers and Roman numerals, validate your Roman strings, and even convert dates like 2025-11-07 → VII • XI • MMXXV.
1. Number ➜ Roman
Roman numeral
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2. Roman ➜ Number
Arabic number
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3. Date ➜ Roman
Useful for inscriptions or fancy headings. We convert day, month, year separately.
Date in Roman numerals
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Roman numeral rules
Roman numerals are built from these symbols:
| Symbol | Value | Notes |
|---|---|---|
| I | 1 | |
| V | 5 | |
| X | 10 | |
| L | 50 | |
| C | 100 | |
| D | 500 | |
| M | 1000 | |
| IV, IX | 4, 9 | Subtractive notation |
| XL, XC | 40, 90 | Subtractive notation |
| CD, CM | 400, 900 | Subtractive notation |
This tool enforces standard modern form (no overlines, no 5000+, no non-standard repetitions).