Converting hexadecimal into binary is very simple. All we need is to remember that hexadecimal is a base 16 number.  This means that each number column can contain 16 characters.  Hexadecimal goes from 0 to F:

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

EG

Using the table – 7 in hex is 0111 in binary.

Using the table – A in hex is 1010 in binary.

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2 digit Hexadecimal to Binary Conversion

In GCSE computer science you will be expected to convert 2 digit hexadecimal into binary.  Again we need to remember that hexadecimal is a base 16 number and each number column can go from 0-9 and A-F. 

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Example 1

Convert hexadecimal number A2 into Binary

Split the hexadecimal number into a 2 column table.

A	2

Using the table above and our knowledge of binary, we can now convert the individual hexadecimal digits into binary. 

A	2
A = 1010	2 = 0010

We now simply combine these 2 nibbles of binary into a byte:

A2 = 1010 0010 in binary

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Example 2

Convert hexadecimal number 28 into binary

2	8
0010	1000

28 = 0010 1000 in binary