Base	Unit	Logarithm	Full Name	Character Set	in bit	References
2	bit	log2	binary digit, binary unit	0,1 (or b,w; or +,-, etc.)	1	C. E. Shannon
e	nat	ln	natural digit, natural unit	-	1.44	Natural logarithms have a base of  e = 2.71828 http://en.wikipedia.org/wiki/Nat (information)
e	e.u. : cal/(mol. K)	ln	(thermodynamic) entropy unit	(atoms, modes of molecular motion, ...)	1.44 k	k is the Boltzmann constant
3		log3	Ternary	0,1,2 (or , etc.)	1.58
4		log4		0,1,2,3 (G,C,A,T in DNA)	2
5		log5	Quintal	0,1,2,3,4	2.32
6		log6		0,1,2,3,4,5	2.58
7		log7		0,1,2,3,4,5,6	2.81
8		log8	octal	0,1,2,3,4,5,6,7	3
9		log9		0,1,2,3,4,5,6,7,8	3.17
10	dec	lg	decimal digit or decimal unit	0,1,2,3,4,5,6,7,8,9	3.32	Decimal logarithms have a base of 10
11					3.46
12					3.59
13					3.70
14					3.81
15					3.91
16	hex	log16	hexadecimal	0-9, A-F	4	http://en.wikipedia.org/wiki/Hexadecimal
20				0-9, A-J (or amino acids in a protein)	4.32
32					5
64					6
128					7
256	byte		byte, character	ASCII Character	8	http://en.wikipedia.org/wiki/Byte
8192			Chinese character	minimum Chinese character set	13
65536			word		16
232			double word		32
264			quad word		64
280			tenbyte		80
2128			paragraph		128
28000000	MB		megabyte		8x106
28000000000	GB		gigabyte		8x109
28000000000000	TB		terabyte		8x1012

Send suggestions and corrections to Shu-Kun Lin by e-mail ([email protected]) with subject title "Entropy and Information Units".
For a list of unit, see http://en.wikipedia.org/wiki/Logarithmic_unit

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Webmaster: Shu-Kun Lin; First prepared: 26 July 2004; revised: 11 December 2007