Free Roman Numeral Converter Online
Convert integers to Roman numerals and Roman numerals back to integers. Supports values from 1 to 3999 (I to MMMCMXCIX).
Roman numerals use seven letters — I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) — and an additive-subtractive system to represent numbers from 1 to 3999. They appear on clock faces, book chapter headings, movie release years, Super Bowl numbering, and formal outlines. The subtractive notation (IV for 4, IX for 9, XL for 40, XC for 90, CD for 400, CM for 900) trips people up. This tool converts integers from 1 to 3999 to their Roman numeral representation and converts any valid Roman numeral string back to an integer.
Roman Numeral Converter
Integer → Roman
Roman → Integer
How to use this roman numeral converter
- To convert an integer to Roman numerals: enter a number from 1 to 3999 and click Convert.
- To convert Roman numerals to an integer: enter the Roman numeral string (e.g., MMXXIV) and click Convert.
- Both directions validate the input and show errors for invalid or out-of-range values.
- Click Copy to put the result on your clipboard.
Common use cases
- Looking up what year a Roman numeral at the end of a film's credits represents
- Writing a chapter or section heading in a document that uses Roman numeral formatting
- Checking the correct Roman numeral for a specific year for a title or publication
- Converting a Super Bowl number, Olympics year, or monarch's regnal number
Frequently asked questions
Why does 4 use IV instead of IIII?
Subtractive notation avoids four repeated symbols in a row. When a smaller value precedes a larger one, the smaller is subtracted: IV means 5 − 1 = 4, IX means 10 − 1 = 9. IIII still appears on many clock faces, but the subtractive form is the modern standard.
What is the largest number that can be represented?
With standard notation (up to three consecutive identical symbols), the largest number is 3999 (MMMCMXCIX). Numbers 4000 and above require extended notation with overlines.
Is zero representable in Roman numerals?
No. Roman numerals have no symbol for zero. The concept of zero as a number was introduced from Indian mathematics through Arabic scholars and adopted in Europe during the Middle Ages.
How do I read a Roman numeral year in a film credit?
Add up the values from right to left, subtracting when a smaller value precedes a larger one. MMXXIV: M(1000)+M(1000)+X(10)+X(10)+IV(4) = 2024.