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.
Without the table for reference we can also convert the hexadecimal into decimal then convert into binary
EG
B in hexadecimal = 11 in decimal
Create a table with the numbers 8, 4, 2, 1 in the upper columns.
| 8 | 4 | 2 | 1 |
Starting at the left hand side, try to subtract the number you have (11 in our case) from the number in the top column – 11 – 8 = 3. Because we can do this we put a 1 in the lower column and move our remainder to the next column.
| 8 | 4 | 2 | 1 |
| 1 | | | |
In the next column we ask if we can subtract 4 from 3. We can’t because this would leave a negative number, so we put a 0 underneath the 4 and carry the 3 over to the next column.
| 8 | 4 | 2 | 1 |
| 1 | 0 | | |
In the next column we ask if 2 can be subtracted 3 without leaving a negative value. It can (3-2 = 1) so we put a 1 value under the 2 column and carry our remainder over to the last column.
| 8 | 4 | 2 | 1 |
| 1 | 0 | 1 | |
In the last column we ask if 1 can be subtracted from 1 without leaving a negative value. It can (1-1=0) so we put a 1 value under the 1 column and our calculation ends because we are left at 0.
| 8 | 4 | 2 | 1 |
| 1 | 0 | 1 | 1 |
We now have our binary number written under the columns – 1011.
B in hexadecimal = 1011 in binary
2 digit Hexadecimal to Binary Conversion
What do we do when we need 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.
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
Example 2
Convert hexadecimal number 28 into binary
| 2 | 8 |
| 0010 | 1000 |
28 = 0010 1000 in binary
4 digit Hexadecimal to Binary Conversion
For the Infrastructure Technician course we need to be able to convert 4 digits of Hexadecimal into a binary so what do we do when we need to convert 4 digits of 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.
Example 3
Convert hexadecimal number A24B into Binary
Split the hexadecimal number into a 4 column table.
| A | 2 | 4 | B |
Using the table above and our knowledge of binary, we can now convert the individual hexadecimal digits into binary.
| A | 2 | 4 | B |
| A = 1100 | 2 = 0010 | 4 = 0100 | 1011 |
A24B = 1100 0010 0100 1011 in binary
Time to test yourself
Now you know how to convert hexadecimal into binary it’s time to test yourself.
