Roman Numeral Converter
Free Roman numeral converter. Convert Arabic numbers to Roman numerals and Roman numerals back to Arabic numbers. Supports values from 1 to 3,999 with a reference chart and conversion rules.
Reference Table
Common Examples
How Do Roman Numerals Work?
Roman numerals use seven basic letters: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). They are combined through addition and subtraction: when a smaller letter precedes a larger one, it is subtracted (IV = 4); when it follows, it is added (VI = 6).
Conversion Rules
Repetition rule: A letter can be repeated up to 3 times in a row (III = 3, but not IIII). Subtraction rule: Only I, X, and C can be placed before a larger numeral to subtract. I before V and X; X before L and C; C before D and M.
Frequently Asked Questions
What is the largest Roman numeral?
Using standard notation, the largest number is 3,999 (MMMCMXCIX). For larger numbers, extended notations with bars or brackets are used.
Is there a Roman numeral for zero?
No, the Romans did not have a symbol for zero. The Roman numeral system starts from 1 (I).