Roman numeral converter
Convert between Roman numerals and decimal numbers
Roman Numeral Converter
Convert between decimal numbers and Roman numerals (1-3999)
TL;DR
What is Roman numeral converter?
Roman numerals are a numeral system from ancient Rome that uses letters from the Latin alphabet: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). They are still used today for clock faces, book chapters, film sequel numbering, copyright years, and formal documents.
Common use cases
- ‣Publishing and design: generate Roman numerals for front-matter page numbering, chapter headings, or copyright years
- ‣Legal documents: some legal and academic citations use Roman numeral section references
- ‣Data parsing: decode Roman numerals from scraped or imported content into integers for sorting or calculation
Frequently asked questions
What is the subtractive principle in Roman numerals?
When a smaller numeral appears before a larger one, it is subtracted rather than added. For example, IV = 4 (5 minus 1) and IX = 9 (10 minus 1). Only I, X, and C can be used subtractively, and only before the next two higher values.
What is the largest number representable in standard Roman numerals?
Standard Roman numerals go up to 3999 (MMMCMXCIX). Numbers above 3999 require non-standard extensions such as a bar over a numeral to multiply it by 1000, which are not universally standardized.