At One Place

42 in Roman numerals

42 in Roman numerals
XLII

42 is written XLII in Roman numerals. That is 3 symbol groups added together, reading left to right from the largest value down.

How it breaks down

XLII = 40 + 1 + 1 = 42
Group Value Subtraction Running total
XL 40 L − X 40
I 1 41
I 1 42

Why the smaller symbol comes first

XLII uses subtractive notation in one place: XL means L minus X, or 40. A smaller symbol placed before a larger one is subtracted from it rather than added, which is why IX is nine and not eleven.

Only six such pairs are valid — IV, IX, XL, XC, CD and CM. That restriction is what makes the notation unambiguous: IIII and IC both look like they should work, but neither is standard, and only one spelling of any number is correct.

The symbols

Symbol Value Used here
I 1 yes — 2×
V 5 no
X 10 yes — 1×
L 50 yes — 1×
C 100 no
D 500 no
M 1,000 no

The same number, other ways

In words
Forty-two
Roman numeral
XLII
Symbol count
4 characters
Binary
101010
Hexadecimal
2A

The numbers either side

Number Roman numeral
40 XL
41 XLI
42 XLII ←
43 XLIII
44 XLIV

Common questions

What is 42 in Roman numerals?
42 is XLII.
What does XLII mean?
XLII is the Roman numeral for 42 — 40 + 1 + 1.
How do you write 42 in Roman numerals?
Take the largest value that fits and repeat until nothing is left: XL (40), then I (1), then I (1). That gives XLII.

Related pages

Sources

  1. Calculated on this page — At One Place

How these figures are compiled and checked