A few well-known reference points:
| Number | Roman Numeral |
|---|
Type a number in either box and the conversion runs automatically in both directions — enter a number to see its Roman numeral, or enter a Roman numeral to see its number, with no separate mode switch to select first.
Standard subtractive notation is used throughout, the same convention used on clock faces and in classical inscriptions: 4 is written IV rather than IIII, and 9 is written IX rather than VIIII, following the rule that a smaller numeral placed before a larger one is subtracted.
The valid range is 1 to 3999. Classical Roman numerals have no symbol for zero and no standard way to represent 4000 or higher without extending the notation with overlines or other conventions, so numbers outside that range aren't supported.
Standard subtractive notation places a smaller numeral before a larger one to mean subtraction, so IV (1 before 5) means 4. IIII was used historically in some contexts, but IV is the standard modern convention this converter follows.
3999 (MMMCMXCIX). Classical Roman numerals have no standard symbol for 4000 or above, or for zero, so those aren't supported.
Yes — type a number to see its Roman numeral, or type a Roman numeral to see its number. Both fields work independently without needing to pick a direction first.
The Roman numeral field automatically displays in uppercase, which is the standard convention — Roman numerals are traditionally written in capital letters.
