Single-precision Floating-point Format

Single-precision floating-point format is a computer number format that occupies 4 bytes (32 bits) in computer memory and represents a wide dynamic range of values by using a floating point.

In IEEE 754-2008 the 32-bit base 2 format is officially referred to as binary32. It was called single in IEEE 754-1985. In older computers, other floating-point formats of 4 bytes were used.

One of the first programming languages to provide single- and double-precision floating-point data types was Fortran. Before the widespread adoption of IEEE 754-1985, the representation and properties of the double float data type depended on the computer manufacturer and computer model.

Single-precision binary floating-point is used due to its wider range over fixed point (of the same bit-width), even if at the cost of precision.

Single precision is known as float in C, C++, C#, Java, and Haskell, and as single in Delphi(Pascal), Visual Basic, and MATLAB. However, float in Python, Ruby, PHP, and OCaml and single in versions of Octave prior to 3.2 refer to double-precision numbers.

Floating-point precisions
IEEE 754
  • 16-bit: Half (binary16)
  • 32-bit: Single (binary32), decimal32
  • 64-bit: Double (binary64), decimal64
  • 128-bit: Quadruple (binary128), decimal128
  • Extended precision formats
  • Minifloat
  • Arbitrary precision

Read more about Single-precision Floating-point Format:  IEEE 754 Single-precision Binary Floating-point Format: Binary32