# Number Prefixes

From S23Wiki

Kilo, mega, giga, tera, and peta are among the list of prefixes that are used to denote the quantity of something, such as, in computing and telecommunications, a byte or a bit. Sometimes called prefix multipliers, these prefixes are also used in electronics and physics. Each multiplier consists of a one-letter abbreviation and the prefix that it stands for.

In communications, electronics, and physics, multipliers are defined in powers of 10 from 10-24 to 1024, proceeding in increments of three orders of magnitude (103 or 1,000). In IT and data storage, multipliers are defined in powers of 2 from 210 to 280, proceeding in increments of ten orders of magnitude (210 or 1,024). These multipliers are denoted in the following table.

Prefix |
Symbol(s) |
Power of 10 |
Power of 2 |

yocto- | y | 10^{-24 *} |
-- |

zepto- | z | 10^{-21 *} |
-- |

atto- | a | 10^{-18 *} |
-- |

femto- | f | 10^{-15 *} |
-- |

pico- | p | 10^{-12 *} |
-- |

nano- | n | 10^{-9 *} |
-- |

micro- | m | 10^{-6 *} |
-- |

milli- | m | 10^{-3 *} |
-- |

centi- | c | 10^{-2 *} |
-- |

deci- | d | 10^{-1 *} |
-- |

(none) | -- | 10^{0} |
2^{0} |

deka- | D | 10^{1 *} |
-- |

hecto- | h | 10^{2 *} |
-- |

kilo- | k or K ^{**} |
10^{3} |
2^{10} |

mega- | M | 10^{6} |
2^{20} |

giga- | G | 10^{9} |
2^{30} |

tera- | T | 10^{12} |
2^{40} |

peta- | P | 10^{15} |
2^{50} |

exa- | E | 10^{18 *} |
2^{60} |

zetta- | Z | 10^{21 *} |
2^{70} |

yotta- | Y | 10^{24 *} |
2^{80} |

* Not generally used to express data speed | |||

** k = 10^{3} and K = 2^{10} |