HEX

HEX

1. Hexadecimal. A base 16 numbering system, which uses the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F. So:

Hex	Decimal	Octal	Binary
0	0	0	0000
1	1	1	0001
2	2	2	0010
3	3	3	0011
4	4	4	0100
5	5	5	0101
6	6	6	0110
7	7	7	0111
8	8	10	1000
9	9	11	1001
A	10	12	1010
B	11	13	1011
C	12	14	1100
D	13	15	1101
E	14	16	1110
F	15	17	1111
10	16	20	10000

Hexadecimal is used in IT because of its close relationship to Binary - as can be seen from the above table each hexadecimal digit corresponds to 4 bits. This means that the hexadecimal numbers 0 to FF cover all the possible eight bit values of a byte (0 to 255 decimal).

Depending on the context, hexidecimal numbers are sometimes prefixed with 0x or # to indicate that the number is hexadecimal and not decimal.

2. Hexagonal. A flat six sided shape.