What does CMXLIII mean?

CMXLIII is the Roman numeral for 943 — 900 + 40 + 1 + 1 + 1.

How do you write 943 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: CM (900), then XL (40), then I (1), then I (1), then I (1). That gives CMXLIII.

943 in Roman numerals

CMXLIII

Number (1–3,999 for numerals)

Roman numeral

943 is written CMXLIII in Roman numerals. That is 5 symbol groups added together, reading left to right from the largest value down.

How it breaks down

CMXLIII = 900 + 40 + 1 + 1 + 1 = 943
Group	Value	Subtraction	Running total
CM	900	M − C	900
XL	40	L − X	940
I	1	—	941
I	1	—	942
I	1	—	943

Why the smaller symbol comes first

CMXLIII uses subtractive notation in 2 places: CM means M minus C, or 900; 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 — 3×
V	5	no
X	10	yes — 1×
L	50	yes — 1×
C	100	yes — 1×
D	500	no
M	1,000	yes — 1×

The same number, other ways

In words: Nine hundred forty-three
Roman numeral: CMXLIII
Symbol count: 7 characters
Binary: 1110101111
Hexadecimal: 3AF

The numbers either side

Number	Roman numeral
941	CMXLI
942	CMXLII
943	CMXLIII ←
944	CMXLIV
945	CMXLV

Common questions

What is 943 in Roman numerals?: 943 is CMXLIII.
What does CMXLIII mean?: CMXLIII is the Roman numeral for 943 — 900 + 40 + 1 + 1 + 1.
How do you write 943 in Roman numerals?: Take the largest value that fits and repeat until nothing is left: CM (900), then XL (40), then I (1), then I (1), then I (1). That gives CMXLIII.

Sources

Calculated on this page — At One Place

How these figures are compiled and checked