What does CDLXVI mean?

CDLXVI is the Roman numeral for 466 — 400 + 50 + 10 + 5 + 1.

How do you write 466 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: CD (400), then L (50), then X (10), then V (5), then I (1). That gives CDLXVI.

466 in Roman numerals

CDLXVI

Number (1–3,999 for numerals)

Roman numeral

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

How it breaks down

CDLXVI = 400 + 50 + 10 + 5 + 1 = 466
Group	Value	Subtraction	Running total
CD	400	D − C	400
L	50	—	450
X	10	—	460
V	5	—	465
I	1	—	466

Why the smaller symbol comes first

CDLXVI uses subtractive notation in one place: CD means D minus C, or 400. 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 — 1×
V	5	yes — 1×
X	10	yes — 1×
L	50	yes — 1×
C	100	yes — 1×
D	500	yes — 1×
M	1,000	no

The same number, other ways

In words: Four hundred sixty-six
Roman numeral: CDLXVI
Symbol count: 6 characters
Binary: 111010010
Hexadecimal: 1D2

The numbers either side

Number	Roman numeral
464	CDLXIV
465	CDLXV
466	CDLXVI ←
467	CDLXVII
468	CDLXVIII

Common questions

What is 466 in Roman numerals?: 466 is CDLXVI.
What does CDLXVI mean?: CDLXVI is the Roman numeral for 466 — 400 + 50 + 10 + 5 + 1.
How do you write 466 in Roman numerals?: Take the largest value that fits and repeat until nothing is left: CD (400), then L (50), then X (10), then V (5), then I (1). That gives CDLXVI.

Sources

Calculated on this page — At One Place

How these figures are compiled and checked