Roman Numeral Converter
Convert between decimal numbers and Roman numerals. Supports values from 1 to 3999.
Frequently Asked Questions
What are Roman numerals?
Roman numerals are a numeral system originating in ancient Rome that uses combinations of letters from the Latin alphabet — I, V, X, L, C, D, and M — to represent values. They are still used today in clock faces, book chapters, movie sequels, and formal outlines.
What is the valid range for Roman numerals?
Standard Roman numerals represent numbers from 1 to 3999. The upper limit exists because there is no single-letter symbol for 5000 in the basic system. Numbers outside this range require extended notation such as vinculum (overline) bars.
How does subtractive notation work?
Subtractive notation places a smaller-value symbol before a larger one to indicate subtraction. For example, IV means 5 − 1 = 4, and IX means 10 − 1 = 9. This avoids repeating a symbol four times (IIII) and keeps numerals compact.