Roman Numeral Converter
Convert to and from Roman numerals
Number → Roman
Roman → Number
About the Roman Numeral Converter
This tool converts between Arabic numerals (1–3999) and Roman numerals in both directions. Type a number to get its Roman representation, or type a Roman numeral to get the Arabic equivalent. Supports all standard Roman numerals including the subtractive notation (IV, IX, XL, XC, CD, CM).
Roman numerals are still used today in clock faces, book chapters, movie sequel numbering, copyright years, and formal document sections. The Roman numeral system uses seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
Frequently asked questions
Why does it stop at 3,999?
Standard Roman numerals only go up to MMMCMXCIX (3,999). Larger values traditionally used a bar over a letter to multiply by 1,000, but that notation isn't in common use today and there's no widely-supported character set for it.
Why is 4 written IV instead of IIII?
Subtractive notation — putting a smaller numeral before a larger one means subtraction. IV = 5 - 1, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900. It keeps numerals shorter than pure additive notation.