- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 26 Jun 2019
A watt (W) is a unit of electrical power. Power is the rate at which physical work of some kind is done, or the amount of energy that is transferred per unit of time. It involves a physical system changing over a specified time.
The watt is named after James Watt, the inventor of the steam engine condenser.
According to the International System of Units (SI), one watt is defined as the energy consumption rate of one joule per second (J/s). One watt is also defined as the current flow of one ampere with a voltage of one volt.
Table of unit prefixes of watt:
(P = power)
|Picowatt||pW||1pW = 10^-12 W||P = 10 pW|
|Nanowatt||nW||1nW = 10^-9 W||P = 10 nW|
|Microwatt||μW||1μW = 10^-6 W||P = 10 μW|
|Watt||W||P = 10 W|
|Kilowatt||kW||1kW = 10^3 W||P = 2 kW|
|Megawatt||MW||1MW = 10^6 W||P = 5 MW|
|Gigawatt||GW||1GW = 10^9 W||P = 5 GW|
 Related articles on Designing Buildings Wiki
Featured articles and news
Organisation revises actions around dealing with COVID-19.
CIOB, NFCC, RIBA, RICS call for changes ahead of Building Safety Bill.
Developments in the Future Homes Standard.
An American chimney feature with a colourful past.
Homes based on need, not ability to pay.
Historic England adds 216 entries to the 'at risk' register.
Will cycling and walking provisions be preserved?
Assembly point levels range from relative to ultimate.
Signs are pointing to a recovery for the construction industry.
Campaigning to change perceptions about American Brutalism.
Sprinkler head configurations can prioritise people or property.
Report from The Carbon Project reveals shortcomings and recommendations.
Advice on how to join the electrotechnical profession.