Convert between Arabic numbers and Roman numerals in both directions, covering the standard range of 1 to 3999.
How it works
- Select whether to convert a Number to Roman or a Roman to Number.
- Input the value you wish to convert.
- The calculator displays the direct conversion instantly.
Frequently asked questions
Why the 1 to 3999 limit?
Standard Roman numerals have no symbol for zero and use bars for thousands above 3999, which this tool does not encode.
How does subtractive notation work?
A smaller numeral before a larger one subtracts: IV = 4, IX = 9, XL = 40.
Where are Roman numerals still used?
Clock faces, book chapters, movie sequels, Super Bowl numbering, and copyright years.