A small instrument for an old notation
Numerals,
translated.
Type a number on either side. The other answers immediately, with the same ceremony Romans gave to inscription.
Enter a value in either field. Conversion happens as you type.
Invalid Roman numerals (like IIII or IC) are rejected with a quiet note.
Press Enter to copy the result of the focused field to your clipboard.
How Roman numerals work
Roman numerals are built from seven letters, each with a fixed value: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, and M = 1,000. You write a number by combining these from largest to smallest and adding the values together — so LXVII is 50 + 10 + 5 + 1 + 1 = 67. To keep numerals short, the same letter is never repeated more than three times in a row; instead, a smaller letter placed before a larger one is subtracted. That is why 4 is IV (one before five) rather than IIII, and 90 is XC (ten before a hundred). Only six such subtractive pairs are valid: IV, IX, XL, XC, CD and CM.
This converter applies those rules in both directions and validates what you type, so malformed numerals like IIII, VV or IC are rejected rather than silently miscounted. The standard range runs from I (1) to MMMCMXCIX (3,999); for larger values, Extended mode uses the vinculum (an overline that multiplies a letter by a thousand) to reach 3,999,999.
Popular conversions
Looking for a specific number? Each has its own page with a full breakdown, number facts and FAQs:
- 2024 in Roman numerals
- 2025 in Roman numerals
- 1000 in Roman numerals
- 100 in Roman numerals
- 49 in Roman numerals
- 2000 in Roman numerals
- 500 in Roman numerals
- 12 in Roman numerals
Or see the complete Roman numerals chart from 1 to 100 and beyond, or read more about the history and use of Roman numerals.