# Prefixes

**Prefixes** are attached to the front of units or other measures to communicate their relative size. This page is a resource on what the different unit prefixes are. Note that these prefixes apply *before* exponents (ex. **centi**meter or **mega**watt). **So a 2 cm ^{3} is the same as 2 (cm)^{3}** and is therefore 2 millionths of a m

^{3}rather than 1 hundredth of a m

^{3}.

Prefix | Value | Name |
---|---|---|

Peta | 10^{15} |
Quadrillion |

Tera- | 10^{12} |
Trillion |

Giga- | 10^{9} |
Billion |

Mega- | 10^{6} |
Million |

Kilo- | 10^{3} |
Thousand |

- | 10^{0} |
One |

Deci- | 10^{-1} |
Tenth |

Centi- | 10^{-2} |
Hundredth |

Milli- | 10^{-3} |
Thousandth |

Micro- | 10^{-6} |
Millionth |

Nano- | 10^{-9} |
Billionth |

Pico- | 10^{-12} |
Trillionth |

Femto- | 10^{-15} |
Quadrillionth |

## For Further Reading

- Units
- Unit conversion page
- Gigatonne
- Megawatt
- Micrometer
- Or explore a random page