Hexadecimal is base 16. This base works exactly the same as base 10 and base 8. Hexadecimal will allow the digits 0 through 15. This gets confusing, however, because the digits 10 through 15 are double digits and raises the question: is 10 a single value or two symbols? To avoid confusion we use other symbols, A through F, to represent the values of 10 through 15. Let's use the hexadecimal number 34CD and convert it to decimal. This number has the value of:

3*163 + 4*162 + 12*161 + 13*160
12288 + 1024 + 192 + 13
13517

So the hexadecimal number 34CD is equivalent to 13517 in base 10 (decimal).

Converting from decimal to hexadecimal is the same process used for octal earlier:

12547 ->
      12547/( 163) -> 3, remainder 259

      259/( 162) -> 1, remainder 3

      3/( 161) -> 0, remainder 3

So 12547 in the decimal number system is equivalent to 3103₁₆ in the hexadecimal system.