What does CDLXXIX mean?

CDLXXIX is the Roman numeral for 479 — 400 + 50 + 10 + 10 + 9.

How do you write 479 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: CD (400), then L (50), then X (10), then X (10), then IX (9). That gives CDLXXIX.

479 in Roman numerals

CDLXXIX

Number (1–3,999 for numerals)

Roman numeral

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

How it breaks down

CDLXXIX = 400 + 50 + 10 + 10 + 9 = 479
Group	Value	Subtraction	Running total
CD	400	D − C	400
L	50	—	450
X	10	—	460
X	10	—	470
IX	9	X − I	479

Why the smaller symbol comes first

CDLXXIX uses subtractive notation in 2 places: CD means D minus C, or 400; IX means X minus I, or 9. 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	no
X	10	yes — 3×
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 seventy-nine
Roman numeral: CDLXXIX
Symbol count: 7 characters
Binary: 111011111
Hexadecimal: 1DF

The numbers either side

Number	Roman numeral
477	CDLXXVII
478	CDLXXVIII
479	CDLXXIX ←
480	CDLXXX
481	CDLXXXI

Common questions

What is 479 in Roman numerals?: 479 is CDLXXIX.
What does CDLXXIX mean?: CDLXXIX is the Roman numeral for 479 — 400 + 50 + 10 + 10 + 9.
How do you write 479 in Roman numerals?: Take the largest value that fits and repeat until nothing is left: CD (400), then L (50), then X (10), then X (10), then IX (9). That gives CDLXXIX.

Sources

Calculated on this page — At One Place

How these figures are compiled and checked