Stax

Roman Numeral Converter

Convert numbers to Roman numerals or decode Roman numerals.

Roman numeral
MMXXIV
Reference chart
NumberRomanNumberRomanNumberRoman
1I4IV5V
9IX10X40XL
50L90XC100C
400CD500D900CM
1000M1900MCM2000MM
2024MMXXIV3000MMM3999MMMCMXCIX

Roman numeral symbols and values

The seven basic symbols are: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. Symbols are generally written from largest to smallest, left to right. When a smaller value precedes a larger one, it uses the subtractive rule.

How to read Roman numerals step by step

  1. Read from left to right, assigning each letter its standard value.
  2. If a letter is followed by a letter of equal or lesser value, add it.
  3. If a letter is followed by a letter of greater value, subtract it (subtractive notation).
  4. Sum all values to get the final number.

Where Roman numerals are used today

  • Clock and watch faces (I through XII)
  • Book front matter (preface, table of contents page numbers)
  • Movie sequels and franchises (Rocky II, Fast X)
  • Super Bowl numbering (Super Bowl LVIII)
  • Monarchs and popes (King Charles III, Pope Francis)
  • Copyright year notices in film credits
  • Outline numbering in legal documents

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 (1), V (5), X (10), L (50), C (100), D (500), and M (1000). They are still used today for clock faces, book chapters, movie sequels, copyright years, and Super Bowl numbering.
What is the subtractive notation rule?
When a smaller numeral appears before a larger one, it is subtracted. For example, IV = 4 (5−1), IX = 9 (10−1), XL = 40 (50−10), XC = 90 (100−10), CD = 400 (500−100), CM = 900 (1000−100). Only these six combinations are valid subtractive pairs.
Why is there no zero in Roman numerals?
Roman numerals evolved from tally marks and were designed for counting objects, not for positional arithmetic. The concept of zero as a placeholder was developed independently in ancient India and later adopted in the Arabic numeral system. Roman numerals have no symbol for zero and cannot easily represent large numbers or fractions.
What is the largest Roman numeral?
In standard notation without extensions, 3999 (MMMCMXCIX) is the largest number representable. Roman numerals cannot represent zero or negative numbers. Extended systems used a bar over a numeral to multiply by 1000 (e.g., V̄ = 5,000), but this is not covered by standard notation.
How do I read the year in Roman numerals?
Break the year into thousands, hundreds, tens, and units. For 2024: 2000 = MM, 0 hundreds = nothing, 20 = XX, 4 = IV → MMXXIV. For 1999: M + CM + XC + IX = MCMXCIX.

Related tools