FAHAQ

Roman Numeral Converter

Convert numbers to Roman numerals and back.

Result
MMXXVI

Free online Roman numeral converter. Convert any number from 1 to 3999 into Roman numerals, or decode a Roman numeral back into a number, with full validation. Runs in your browser.

How to use the Roman Numeral Converter

  1. 01Choose a direction: Number → Roman or Roman → Number.
  2. 02Type your value.
  3. 03The converted result appears instantly, with invalid input flagged.
  4. 04Copy the result.

Frequently asked questions

What range of numbers is supported?

Standard Roman numerals represent 1 to 3999. There is no symbol for zero and no standard way to write larger numbers without bars, so the converter covers 1–3999.

Does it reject invalid numerals?

Yes. Inputs like IIII or VX are rejected because the tool validates by converting back and checking it matches the canonical form.