Roman Numeral Calculator
Roman Numeral Converter
Convert between Arabic numbers and Roman numerals with ease.
Number to Roman Numeral
Convert Arabic numbers to Roman numerals using additive and subtractive principles
MMXXIV
Roman numeral
Understanding Roman Numerals
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet.
Basic Symbols and Values
I
1
V
5
X
10
L
50
C
100
D
500
M
1000
Rules of Roman Numerals
- Addition Rule: When a smaller numeral is after a larger numeral, add them (e.g., VI = 5 + 1 = 6)
- Subtraction Rule: When a smaller numeral is before a larger numeral, subtract it (e.g., IV = 5 - 1 = 4)
- Repetition Rule: No more than three identical numerals in a row (e.g., III = 3, but 4 is IV not IIII)
- Order of Magnitude: Only I, X, and C can be used for subtraction, and only before the next two higher numerals
Common Examples
IV
4
IX
9
XL
40
XC
90
CD
400
CM
900
Modern Usage
While Roman numerals are no longer used for everyday arithmetic, they still appear in various contexts today: clock faces, book chapters and volumes, movie sequels, sporting events (like Super Bowl LVII), monarch names (King Charles III), and building cornerstones.