1 Astronomical Unit (AU) = 1.496 x 10^{11} m ≃ 1.5 x 10^{11} m |

1 Light Year (ly) = 9.46 x 10^{15} m = 6.3 x 10^{4} AU |

1 par sec = 3.1 x 10^{16} m = 3.26 ly |

1 inch = 0.0254 m |

1 foot = 0.3048 m |

1 yard = 0.9144 m |

1 mile = 1.609 x 10^{3} m |

1 nautical mile = 1.852 x 10^{3} m |

1 fermi or femtometre (fm) = 10^{-15} m |

1 X-ray unit (X) = 10^{-13} m |

1 picometre (pm) = 10^{-12} m |

1 angstrom (Å) = 10^{-10} m |

1 nanometre (nm) = 10^{-9} m |

1 micron or micro-metre (µm) = 10^{-6} m |

1 millimetre (mm) = 10^{-3} m |

1 centimetre (cm) = 10^{-2} m |

1 decimetre (dm) = 10^{-1} m |

1 decametre (dam) = 10 m |

1 hectometre (hm) = 10^{2} m |

1 kilometre (km) = 10^{3} m |

1 megametre (Mm) = 10^{6} m |

1 gigametre (Gm) = 10^{9} m |

1 terametre (Tm) = 10^{12} m |

1 barn = 10^{-28} m^{2} |

1 acre = 4047 m^{2} |

1 hectare = 10^{4} m^{2} |

1 tonne or metric ton = 1000 kg |

1 quintal = 100 kg |

1 slug = 14.57 kg |

1 atomic mass unit (a.m.u) = 1.66 x 10^{-27} kg |

1 solar year = 365.25 average solar days = 366.25 sidereal day |

1 Lunar Month = 27.3 days |

1 shake = 10^{-8} sec |

1 bar = 760 torr |