Definition[change | edit source]
The watt is the rate a source of energy uses or produces one joule during one second, so the same quantity may be referred to as a joule per second, with the symbol J/s. It can also be written as kg·m2·s−3.
It is equivalent to one volt ampere (1 V·A) or 1/746 of a horsepower. The power of a light bulb is measured in watts. LEDs have much smaller consumption of power. Example small led can be used by 0.015 watts what can be also written 15 milliwatts.
1000 watts is called a kilowatt, written as kW. It is also known as (103) watts. In many countries, electric bills are based on how many kilowatt-hours are being used.
1000000 watts is called a megawatt, written as MW. It is also known as (106) watts. This is used to describe how much electricity is needed by a large town.