Monu Tools

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers (1 to 3999).

How to use the Roman Numerals

  1. 01

    Choose whether to convert a number to Roman or a Roman numeral to a number.

  2. 02

    Type your value.

  3. 03

    Copy the converted result.

Frequently asked questions

What range is supported?

Standard Roman numerals from 1 (I) to 3999 (MMMCMXCIX). The Romans had no zero and no standard notation above 3999.

How does Roman numeral subtraction work?

A smaller numeral before a larger one is subtracted, so IV is 4 and IX is 9. The converter validates this, rejecting forms like IIII or VV.

Are lowercase letters accepted?

Yes. Roman numerals are read case-insensitively, so mcmlxxxiv and MCMLXXXIV both give 1984.

About this tool

A two-way Roman numeral converter for numbers from 1 to 3999, validating input so only well-formed numerals are accepted.

Useful for dates, clock faces, book chapters and copyright years. It runs instantly in your browser.

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