Difference between Single Precision and Double Precision

According to IEEE standard, floating-point number is represented in two ways:

Precision | Base | Sign | Exponent | Significand |

Single precision | 2 | 1 | 8 | 23+1 |

Double precision | 2 | 1 | 11 | 52+1 |

**1. Single Precision:**

Single Precision is a format proposed by IEEE for representation of floating-point number. It occupies 32 bits in computer memory.

**2. Double Precision:**

Double Precision is also a format given by IEEE for representation of floating-point number. It occupies 64 bits in computer memory.

**Difference between Single and Double Precision:**

SINGLE PRECISION | DOUBLE PRECISION |
---|---|

In single precision, 32 bits are used to represent floating-point number. | In double precision, 64 bits are used to represent floating-point number. |

It uses 8 bits for exponent. | It uses 11 bits for exponent. |

In single precision, 23 bits are used for mantissa. | In double precision, 52 bits are used for mantissa. |

Bias number is 127. | Bias number is 1023. |

Range of numbers in single precision : 2^(-126) to 2^(+127) | Range of numbers in double precision : 2^(-1022) to 2^(+1023) |

This is used where precision matters less. | This is used where precision matters more. |

It is used for wide representation. | It is used for minimization of approximation. |

It is used in simple programs like games. | It is used in complex programs like scientific calculator. |

This is called binary32. | This is called binary64. |

Please refer Floating Point Representation for details.