What does CCCXL mean?

CCCXL is the Roman numeral for 340 — 100 + 100 + 100 + 40.

How do you write 340 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: C (100), then C (100), then C (100), then XL (40). That gives CCCXL.

340 in Roman numerals

CCCXL

Number (1–3,999 for numerals)

Roman numeral

340 is written CCCXL in Roman numerals. That is 4 symbol groups added together, reading left to right from the largest value down.

How it breaks down

CCCXL = 100 + 100 + 100 + 40 = 340
Group	Value	Subtraction	Running total
C	100	—	100
C	100	—	200
C	100	—	300
XL	40	L − X	340

Why the smaller symbol comes first

CCCXL 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	no
V	5	no
X	10	yes — 1×
L	50	yes — 1×
C	100	yes — 3×
D	500	no
M	1,000	no

The same number, other ways

In words: Three hundred forty
Roman numeral: CCCXL
Symbol count: 5 characters
Binary: 101010100
Hexadecimal: 154

The numbers either side

Number	Roman numeral
338	CCCXXXVIII
339	CCCXXXIX
340	CCCXL ←
341	CCCXLI
342	CCCXLII

Common questions

What is 340 in Roman numerals?: 340 is CCCXL.
What does CCCXL mean?: CCCXL is the Roman numeral for 340 — 100 + 100 + 100 + 40.
How do you write 340 in Roman numerals?: Take the largest value that fits and repeat until nothing is left: C (100), then C (100), then C (100), then XL (40). That gives CCCXL.

Sources

Calculated on this page — At One Place

How these figures are compiled and checked