Roman Numeral Converter

Type a number or a Roman numeral — it converts both ways as you type.

Runs in your browser — nothing is uploaded

How to use Roman Numeral Converter

  1. Type a number (1–3999) in the left box, or a Roman numeral in the right box.
  2. The other box updates instantly.

Questions

Why only up to 3,999?

Standard Roman numerals have no symbol above M (1000) and use at most three repeats, so 3,999 (MMMCMXCIX) is the largest regular value.