# Watt-hour

SI multiples of watt-hour | ||||||
---|---|---|---|---|---|---|

Multiple | Name | Symbol | Multiple | Name | Symbol | |

10^{0}
| watt-hour | W·h | ||||

10^{1}
| decawatt-hour | daW·h | 10^{–1}
| deciwatt-hour | dW·h | |

10^{2}
| hectowatt-hour | hW·h | 10^{–2}
| centiwatt-hour | cW·h | |

10^{3}
| kilowatt-hour | kW·h | 10^{–3}
| milliwatt-hour | mW·h | |

10^{6}
| megawatt-hour | MW·h | 10^{–6}
| microwatt-hour | µW·h | |

10^{9}
| gigawatt-hour | GW·h | 10^{–9}
| nanowatt-hour | nW·h | |

10^{12}
| terawatt-hour | TW·h | 10^{–12}
| picowatt-hour | pW·h | |

10^{15}
| petawatt-hour | PW·h | 10^{–15}
| femtowatt-hour | fW·h | |

10^{18}
| exawatt-hour | EW·h | 10^{–18}
| attowatt-hour | aW·h | |

10^{21}
| zettawatt-hour | ZW·h | 10^{–21}
| zeptowatt-hour | zW·h | |

10^{24}
| yottawatt-hour | YW·h | 10^{–24}
| yoctowatt-hour | yW·h |

### Definition

The **watt-hour** (symbol W·h) is a unit of energy commonly used to measure electricity. One watt-hour is the amount of electrical energy equivalent to a one-watt load drawing power for one hour. For example, a 100-watt light bulb uses 100 watt-hours of energy every hour. The is commonly used in the form of the **kilowatt-hour**, which is 1,000 watt-hours. The watt-hour It is not an SI unit, despite being based on the watt. The SI unit of energy is the joule (J), equal to one watt-second.

In the inch-pounds unit system, a watt-hour is equivalent to 3.412 Btu.

### Further reading

- How Many? A Dictionary of Units of Measurement, Russ Rowlett, Center for Mathematics and Science Education, University of North Carolina at Chapel Hill
- SI base units and SI derived units, the Physics Laboratory, National Institute of Standards and Technology
- Energy conversion tool at
**unitconversion.org**

## 0 Comments