Roman Numerals

Convert between Roman numerals and Arabic numbers. Explore the ancient numbering system used by the Romans.

Enter a number between 1 and 3999. Traditional Roman numerals don't support numbers above 3999.

Roman Numeral Rules

1
Basic symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000
2
Additive rule: Symbols are added when a smaller value follows a larger one (e.g., VI = 6)
3
Subtractive rule: Smaller symbols before larger ones subtract (e.g., IV = 4, IX = 9)
4
Repetition limit: I, X, C, M can repeat up to 3 times; V, L, D cannot repeat
5
Largest first: Always place the largest symbols on the left

Common Roman Numerals

I
1
V
5
X
10
L
50
C
100
D
500
M
1000
IV
4
IX
9
XL
40
XC
90
CD
400
CM
900
MMXXIV
2024
MCMXCIX
1999

History of Roman Numerals

Origins

Roman numerals originated in ancient Rome around 500 BC. They were the standard numbering system used in the Roman Empire and remained in use throughout Europe for centuries.

Roman numeral evolution:
  • 500 BC: Early forms appear
  • 1st century: Standardized system
  • Middle Ages: Widely used in Europe
  • Modern era: Limited use today

Modern Uses

  • Clocks and watches: Traditional timepieces
  • Book chapters: Volume and chapter numbering
  • Movie sequels: Film series numbering
  • Monarch names: King Edward VI, Louis XIV
  • Copyright dates: © MMXXIV
  • Sports events: Super Bowl LIV

Fun Facts

  • Zero: Roman numerals had no symbol for zero (nulla)
  • Fractions: Romans used separate symbols for fractions (uncia = 1/12)
  • Large numbers: Very large numbers required special notation
  • Vinculum: A line over numerals multiplied by 1000 (e.g., V̄ = 5000)
  • Subtractive notation: First used in the 1st century BC
  • Unicode: Roman numerals have dedicated Unicode characters