Roman Numeral Converter

Convert any number to Roman numerals, or decode one back to a number.

Standard Roman numerals only go up to 3,999 (MMMCMXCIX) — there's no traditional symbol for 4,000 or beyond.

Result
MCMXCIV

Roman numerals use a subtractive principle for four of the digits in each place (like IV for 4, IX for 9) — a smaller symbol before a larger one means subtract rather than add.

A worked example

The year 1994 is written as MCMXCIV — combining M (1000), CM (900), XC (90), and IV (4).

Frequently asked questions

Why is 4 written as IV instead of IIII?

Roman numerals use a subtractive shorthand for four specific values in each place (4, 9, 40, 90, 400, 900) — placing a smaller symbol immediately before a larger one means subtract, which keeps numbers more compact than repeating a symbol four times.

What's the largest number standard Roman numerals can represent?

3,999, written as MMMCMXCIX — there's no traditional single symbol for 5,000 or higher in the standard system, though historical extensions using overlines existed for larger numbers.