Numbers: Roman numerals

On this page

• Basic Roman numerals
• Rules for combining numerals
• Table of Roman numerals
• Uses of Roman numerals
• Additional information

Basic Roman numerals

There are seven basic Roman numerals, represented by letters:

• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• D = 500
• M = 1000

Rules for combining numerals

The basic Roman numerals can be combined to represent different numeric values, according to the following rules:

• Identical side-by-side numerals are added together.
  • II (1 + 1) = 2
• When a larger numeral comes before a smaller one, they’re added together.
  • VI (5 + 1) = 6
• When a smaller numeral comes before a larger one, the smaller value is subtracted from the larger.
  • IX (10 - 1) = 9
• Only I, X and C can be subtracted from another numeral, and only from the next two numerals that are larger than it.
  • XCIX [not IC] = 99
• V, L, and D (the numerals that represent 5, 50 and 500, respectively) are never written before a larger numeral and hence never subtracted from a larger numeral. They’re also never repeated.
  • CML [not LM] = 950
  • M [not DD] = 1000
• The same symbol cannot be used more than three times in succession (except for the numeral M). Therefore, the number 4 is normally represented as IV (5 - 1), and not as IIII. However, in keeping with an old tradition, the numeral IIII is sometimes used on clock dials.
• For larger numbers, a horizontal bar over a Roman numeral multiplies its value by 1000. This bar is called a vinculum.
  • V = 5000
  • D = 500 000

Table of Roman numerals

The following table provides a summary of Roman numerals, along with their corresponding numeric values:

Table of Roman Numerals and Their Corresponding Numeric Values

Roman numeral	Numeric value
I	1
II	2
III	3
IV	4
V	5
VI	6
VII	7
VIII	8
IX	9
X	10
XX	20
XXX	30
XL	40
L	50
LX	60
LXX	70
LXXX	80
XC	90
C	100
CC	200
CCC	300
CD	400
D	500
M	1000
MD	1500
MM	2000
MMM	3000
IV	4000
V	5000
X	10,000
C	100,000
D	500,000
M	1,000,000

Uses of Roman numerals

Although Roman numerals are becoming increasingly rare, they’re still used in a number of cases.

Roman numerals are used after the names of rulers, aristocrats, ships, racing cars and space vehicles:

• Charles IV
• Pius XII
• Bluenose II
• Saturn V

Roman numerals are often used in Government of Canada Statutes:

• Schedule IV
• Part III

Roman numerals are sometimes used for the numbers of volumes, chapters, acts, tables, illustrations and other parts of a book or play, although they’re now often replaced with Arabic numerals:

• Psalm XXIII
• Volume XII
• Appendix III
• Act II, Scene iii [act number in upper case, scene number in lower case]

Roman numerals are also sometimes used in the titles of TV and film series:

• Jurassic Park III

Lower case Roman numerals may be used for page numbers in preliminary matter (preface, foreword, table of contents, etc.) and subclauses of legal documents:

• page xi of the Preface

Roman numerals are also used for years (in very formal contexts), centuries and recurring events of major importance:

• MCMLXIV
• XIX century
• XXIII Olympiad

Note: Ordinal forms (st, nd, th, etc.) should not be used with Roman numerals:

• XIX century [not XIXth century]
• XXII Olympiad [not XXIInd Olympiad]

Additional information

• Decoding Roman numerals (quiz)