Overview#Hexadecimal (also base 16, or hex) is a positional numeral system with a radix, or base, of 16.
Hexadecimal uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a, b, c, d, e, f) to represent values ten to fifteen.
Hexadecimal numerals are widely used by computer system designers and programmers. Several different notations are used to represent Hexadecimal constants in computing languages; the prefix "0x" is widespread due to its use in Unix and C (and related operating systems and languages). Alternatively, some authors denote Hexadecimal values using a suffix or subscript.
For example, one could write 0x2AF3 or 2AF316, depending on the choice of notation.
As an example, the Hexadecimal number 2AF316 can be converted to an equivalent decimal representation. Observe that 2AF316 is equal to a sum of (200016 + A0016 + F016 + 316)
Each Hexadecimal digit represents four binary digits (bits), and the primary use of Hexadecimal notation is a human-friendly representation of binary-coded values in computing and digital electronics.
One Hexadecimal digit represents a nibble, which is half of an octet or byte (8 bits).
For example, byte values can range from 0 to 255 (decimal), but may be more conveniently represented as two Hexadecimal digits in the range 00 to FF.
Hexadecimal is also commonly used to represent computer memory addresses.