Hexadecimal is a base 16 counting system meaning it can represent the numbers from 0 to 15 in each column. For numbers bigger than 9 the letters a to f are used as seen in the table below.
| Decimal | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| Hexadecimal | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
This page deals with 2 digit hex numbers. With a hex number the digit in the column on the right is the number of 1s in a number with the lowest value being 0 and the highest being F representing 15. The second column therefore represents the numer of 16s in the number.
| Column_heading | 16s | 1s |
| Value | C | 4 |
The value C4 shown above is equal to C x 16 + 4 = 12 x 16 + 4 = 192 + 4 = 196.
Use the area below to generate a random hex number to practice converting numbers from hexadecimal to decimal.
For our example let's convert the hexadecimal number A7 to it's decimal equivalent.
The formula for this is decimal = first hex digit x 16 + second hex digit. To use the formula simply slot in the hex digits and if they are letters convert them to their decimal equivalent e.g. A = 10, B= 11 etc. Then work through the maths to the solution.
So in our example decimal = A x 16 + 7 = 10 x 16 + 7 = 160 + 7 = 167.
Therefore our A7 in hexadecimal is equivalent to 167 in decimal.
Click the button to get a number to convert
Enter the decimal equivalent above.