Roman Numeral Converter
Convert numbers to Roman numerals and back, with instant results for values from 1 to 3999.
Enter a number:
How to convert Roman numerals
- Choose a mode: Number to Roman or Roman to Number.
- Enter a number between 1 and 3999, or a Roman numeral.
- The result updates instantly as you type.
- Copy the result when you are done.
FAQs
What is the largest number the converter accepts?
The tool converts numbers from 1 to 3999. Roman numerals have no standard form for zero or for values of 4000 and above without special notation.
How are subtractive combinations handled?
The converter understands the standard subtractive pairs like IV, IX, XL, XC, CD and CM, so IV is 4 and IX is 9.
Does it accept lowercase letters?
Yes. Lowercase letters are treated the same as uppercase, so "mmxxiv" converts just like "MMXXIV".
Is the converter free?
Yes. Every Handio tool is free and runs entirely in your browser, with no sign-up and no data uploads.
Related Tools
Why convert to Roman numerals?
Roman numerals still show up in dates, chapter numbers, clocks, film titles and page numbering. Converting them by hand is fiddly, especially once subtractive notation is involved.
- Read the Roman numerals on a building corner or clock face.
- Convert a year for a title page, tattoo or design.
- Check the value of a chapter or section numbered in Roman numerals.
Tips and Limits
The tool converts whole numbers from 1 to 3999 only, because zero and values of 4000 or more have no standard Roman form. Letters are case-insensitive and the result updates live as you type, entirely in your browser.