Roman Numeral Converter
Convert whole numbers to Roman numerals and back.
Results update as you type.
About this calculator
A Roman numeral converter turns an ordinary number (1 to 3,999) into Roman numerals like MCMLXXXIV, or reads a Roman numeral back into a number. Romans built values from the symbols I, V, X, L, C, D and M using a subtractive rule (IV = 4, IX = 9).
Frequently asked questions
How does the subtractive rule work?
When a smaller symbol comes before a larger one it is subtracted: IV is 4 (5 − 1), IX is 9, XL is 40 and CM is 900. Otherwise symbols are added left to right.
Why is the maximum 3,999?
Standard Roman numerals only go up to 3,999 (MMMCMXCIX). Representing 4,000 or more needs an overline notation that most fonts and forms cannot show.
Is there a zero in Roman numerals?
No. The Roman system has no symbol for zero and no place value, which is one reason it was eventually replaced by Arabic numerals for arithmetic.
Results are estimates for general guidance only, not financial, medical or tax advice.