Roman Numeral Calculator
Enter a number from 1 to 3999 to convert it into Roman numerals.
How numbers convert to Roman numerals
Roman numerals use combinations of seven letters — I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) — built by repeatedly subtracting the largest possible value (including special subtractive pairs like IV for 4 and IX for 9) and appending its symbol until nothing remains.
This calculator works for numbers from 1 to 3999, the traditional range of standard Roman numerals — numbers at or above 4000 require special notation (like a bar over a numeral to multiply it by 1000) that isn't commonly used in everyday contexts.
Frequently asked questions
Why is 4 written as IV instead of IIII?
The subtractive notation (IV, IX, XL, XC, CD, CM) was adopted to shorten numerals that would otherwise need four repeated symbols. IIII does appear historically and on some clock faces for aesthetic/practical reasons, but IV is the standard modern form.
What's the largest number this calculator supports?
3999 (MMMCMXCIX), since standard Roman numerals don't have symbols beyond M (1000), and repeating M more than three times isn't conventional. Larger numbers require special historical notations rarely used today.
Where are Roman numerals still commonly used today?
Common uses include clock faces, movie and book copyright years, Super Bowl and Olympic Games numbering, outline/chapter numbering, and monarch or pope naming (like Elizabeth II or John Paul II).