Roman Numeral Converter
Convert numbers to Roman numerals and back in a click.
Loading tool…
Convert between ordinary numbers and Roman numerals in both directions. Type a number to get its Roman numeral (up to 3,999), or enter a Roman numeral to get the number. It is handy for dates, names, chapters and design. The conversion runs live in your browser.
The rules behind the letters
Seven letters carry all the values: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1000. They are written largest first and added together, so MMXXIV is 1000 plus 1000 plus 10 plus 10 plus 1 plus 5 minus 1. The subtraction rule is what makes them awkward: a smaller value placed before a larger one is subtracted, which is why IV is four and IX is nine.
Where you still meet them
- Film and game titles, and the copyright year in film credits.
- Monarchs, popes and family names, as in Elizabeth II.
- Clock faces, book chapters and formal document sections.
- Building cornerstones and monuments, where they look permanent.
- Super Bowl numbering, which is the reason many people look them up at all.
The limits of the system
Roman numerals have no zero and no way to write a negative number or a fraction, which is precisely why they were replaced for arithmetic. Standard notation also stops at 3999, because writing 4000 would need four M characters in a row and the convention does not allow it. Larger numbers required overline marks that are rarely used today, so any converter working in the standard system tops out there.
How to use Roman Numeral Converter
- 1
Enter a number or a Roman numeral.
- 2
See the converted value instantly.
- 3
Copy the result.
Frequently asked questions
Standard Roman numerals from 1 to 3,999.