Converts numbers between Arabic (standard) and Roman numeral notation in both directions. Supports the standard range of 1 to 3,999 (MMMCMXCIX). Validates Roman numeral input for correct subtractive notation. Useful for document formatting, chapter numbering, and historical date conversion.
| Value | Symbol | Value | Symbol |
|---|---|---|---|
| 1000 | M | 50 | L |
| 900 | CM | 40 | XL |
| 500 | D | 10 | X |
| 400 | CD | 9 | IX |
| 100 | C | 5 | V |
| 90 | XC | 4 | IV |
Enter a number or Roman numeral to convert instantly in either direction.
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