7 Major Difference Between Single And Double Precision Floating-Point Format

SHARE

What Is Single Precision?

Single precision is a format proposed by IEEE for representation of floating-point number. It occupies 32 bits in a computer memory; it represents a wide dynamic range of numeric values by using a floating radix point. A floating-point variable can represent a wider range of numbers than a fixed-point variable of the same bit width at the cost of precision.  

In the IEEE 754-2008 standard, the 32-bit base-2 format is officially referred to as binary 32; it was called single in IEE 754-1985. IEEE 754 specifies additional floating-point types such as 64-bit base-2 double precision and more recently, base-10 representations.

What You Need To Know About Single Precision

  1. In single precision, 32 bits are used to represent floating-point number.
  2. It uses 8 bits for exponent.
  3. It is widely used in games and programs requiring less precision and wide representation.
  4. In single precision, 23 bits are used for mantissa.
  5. Bias number is 127.
  6. Range of numbers in single precision: 2^(-126) to 2^(+127).
  7. Single precision is used where precision matters less.

What Is Double Precision?

Double-precision is a computer number format usually occupying 64 bits in computer memory; it represents a wide dynamic range of numeric values by using a floating radix point. Floating point is used to represent fractional values or when a wider range is required than is provided by fixed point (of the same bit width), even if at the cost of precision. Double precision may be chosen when the range or precision of single precision would be insufficient.

In the IEE 754-2008 standard, the 64-bit base-2 format is officially referred to as binary64; it was called double in IEEE 754-1985. IEEE 754 species additional floating-point formats, including 32-bit base-2 single precision and more recently, base-10 representations.

What You Need To Know About Double Precision

  1. In double precision, 64 bits are used to represent floating-point number.
  2. It uses 11 bits for exponent.
  3. It is used in complex programs like scientific calculator where precision is all that matters and approximation is to be minimized.
  4. In double precision, 52 bits are used for mantissa.
  5. Bias number is 1023.
  6. Range of numbers in double precision: 2^(-1022) to 2^(+1023).
  7. Double precision is used where precision matters more.

Major Difference Between Single And Double Precision In Tabular Form

BASIS OF COMPARISON SINGLE PRECISION DOUBLE PRECISION
Description In single precision, 32 bits are used to represent floating-point number.   In double precision, 64 bits are used to represent floating-point number.  
Bits It uses 8 bits for exponent.   It uses 11 bits for exponent.  
Application It is widely used in games and programs requiring less precision and wide representation.   It is used in complex programs like scientific calculator where precision is all that matters and approximation is to be minimized.  
Mantissa In single precision, 23 bits are used for mantissa.   In double precision, 52 bits are used for mantissa.  
Bias Number Bias number is 127.   Bias number is 1023.  
Range Of Numbers Range of numbers in single precision: 2^(-126) to 2^(+127).   Range of numbers in double precision: 2^(-1022) to 2^(+1023).  
Use Single precision is used where precision matters less.   Double precision is used where precision matters more.