Reference Table
Roman Numeral Converter
Roman numerals are a numeral system originating in ancient Rome, using combinations of letters (I, V, X, L, C, D, M) to represent values. They are still used today in clock faces, book chapters, movie sequels, and formal outlines. This tool converts between standard Arabic numbers (1–3999) and Roman numerals.
FAQ
Q: What are Roman numerals?
A: Roman numerals are a number system that originated in ancient Rome. They use seven basic symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numbers are formed by combining these symbols using addition and subtraction rules.
Q: How does subtraction work in Roman numerals?
A: When a smaller value appears before a larger value, you subtract it. For example, IV = 4 (5 minus 1), IX = 9 (10 minus 1), XL = 40 (50 minus 10), XC = 90 (100 minus 10), CD = 400 (500 minus 100), and CM = 900 (1000 minus 100).
Q: Why is the maximum 3999?
A: Standard Roman numeral notation cannot represent numbers 4000 and above without additional conventions such as vinculum (overline). The number 3999, written as MMMCMXCIX, is the largest number expressible in basic Roman numerals.
Q: Are Roman numerals still used today?
A: Yes. Roman numerals are commonly used for clock faces, chapter numbering in books, copyright dates on films and TV shows, names of monarchs and popes (e.g., Elizabeth II), Super Bowl numbering, and formal document outlines.
Q: What is the Roman numeral for zero?
A: There is no Roman numeral for zero. The Roman numeral system was developed before the concept of zero was introduced to European mathematics. The word "nulla" (meaning "none") was sometimes used in medieval contexts.