Hexadecimal Number System

The hexadecimal number system is a base-16 system that uses sixteen symbols: the digits 0 to 9 and the letters A to F, where A = 10 and F = 15. Each hexadecimal digit represents exactly four binary digits, so it is a short, readable way to write binary values.

Hexadecimal is used for memory addresses, colour codes in web design (#FF5733), MAC addresses, character codes and error codes. It is often written with a 0x prefix, as in 0x1F. To convert to decimal, multiply each digit by a power of 16: 0x1F = 1 × 16 + 15 = 31.

Hex   Binary      Decimal
0x9   1001        9
0xA   1010        10
0xF   1111        15
0x1F  0001 1111   31
0xFF  1111 1111   255