What Is a Roman Numeral Converter?
A Roman numeral converter translates between standard Arabic (decimal) numbers and Roman numerals. Roman numerals use the letters I, V, X, L, C, D, and M to represent values 1, 5, 10, 50, 100, 500, and 1000 respectively. This tool supports values from 1 to 3999, which covers the classic Roman numeral system. It is useful for students, historians, and anyone working with clock faces, chapter numbering, or copyright year notation.
How Roman Numerals Work
Roman numerals follow two key rules: additive notation (e.g., VI = 5 + 1 = 6) and subtractive notation (e.g., IV = 5 - 1 = 4). The subtractive principle applies to specific pairs: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). Numbers are written from largest to smallest value, left to right. Understanding these rules helps you read dates on buildings, movie credits, and classical texts.
Frequently Asked Questions
What is the largest number you can write in Roman numerals?
Using the standard system without vinculum (overline) notation, the largest number is 3999 (MMMCMXCIX). Extended Roman numerals use an overline to multiply by 1000, but that system is rarely used today.
Why is 4 written as IV and not IIII?
The subtractive principle was adopted to keep numerals shorter and easier to read. However, IIII is sometimes used on clock faces for aesthetic balance with VIII on the opposite side, a tradition dating back centuries.