Roman numerals use letters instead of digits. There are only seven symbols — combine them to make any number.

The seven symbols

SymbolValue
I1
V5
X10
L50
C100
D500
M1,000

Numbers 1–20

I
1 · one
II
2 · two
III
3 · three
IV
4 · four
V
5 · five
VI
6 · six
VII
7 · seven
VIII
8 · eight
IX
9 · nine
X
10 · ten
XI
11 · eleven
XII
12 · twelve
XIII
13 · thirteen
XIV
14 · fourteen
XV
15 · fifteen
XVI
16 · sixteen
XVII
17 · seventeen
XVIII
18 · eighteen
XIX
19 · nineteen
XX
20 · twenty
The addition & subtraction rule: A smaller symbol AFTER a bigger one is added: VI = 5+1 = 6. A smaller symbol BEFORE a bigger one is subtracted: IV = 5-1 = 4, IX = 10-1 = 9. Only I, X and C are ever used this way (before V/X, X/L, or C/D/M).

Where you still see Roman numerals today

ContextExample
Clock facesSome watches and clocks show IV, IX or XII instead of 4, 9 or 12.
Monarchs & popesQueen Elizabeth II, King Charles III, Pope Francis I.
Sequels & episodesRocky IV, Star Wars: Episode IV.
Super BowlsSuper Bowl LVIII (58) was played in 2024.
CenturiesThe XXI century = the 21st century.
Book & film creditsChapter IV, © MMXXIV (2024).

Exercise — convert the numbers

Type the Roman numeral (capital letters) or the Arabic number.

1.7 =
2.9 =
3.14 =
4.XVIII =
5.IV =
6.XI =