Roman Numeral Converter

Roman Numeral Converter turns any whole number from 1 to 3999 into its Roman numeral and converts any Roman numeral back to a number — instantly, with a clear breakdown of every part. It works completely offline and nothing you type ever leaves your phone.

WHAT YOU CAN DO
• Convert a number to a Roman numeral: type 2024 and read MMXXIV
• Convert a Roman numeral to a number: enter MMXXIV and get 2024
• See the place-value breakdown of every result, for example MM = 2000, XX = 20, IV = 4
• Browse a reference chart of the seven base symbols and common values
• Learn the rules with a short, plain-language guide

HOW ROMAN NUMERALS WORK
The system uses seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Symbols are written from largest to smallest and added together, and a letter may repeat up to three times. To avoid four in a row, a smaller symbol placed before a larger one is subtracted — this is the subtractive rule that gives IV = 4, IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900. For example, 49 is written XLIX (40 + 9).

WHY IT STOPS AT 3999
Roman numerals have no symbol for zero — the system counts amounts rather than holding place values. Using only the seven basic letters, the largest value you can write is MMMCMXCIX, which is 3999. Larger numbers historically used an overline (vinculum) to multiply by a thousand; this converter keeps to the standard letters, so it covers 1 to 3999.

BUILT FOR CLARITY
A clean design in warm imperial colors puts the result first, in a classic serif style, with the breakdown right below it. The app includes light and dark themes, is a tiny download, needs no account and asks for no personal permissions.

A HANDY REFERENCE AND LEARNING TOOL
Roman numerals still appear on clock faces, book chapters, film copyright years, monarch and pope names, sporting events and building cornerstones. Whether you are decoding one or teaching the system, this app gives you the answer and shows the working. It is provided for general education and reference and comes without warranty of accuracy for any official use.

PRIVACY AND ADS
The app collects no personal data and works fully offline. Ads are served by Google AdMob, which may use your device advertising identifier as described in Google's policies.

Download Roman Numeral Converter for a fast, clear way to read and write Roman numerals.