100W

100 watts (W) is a unit of power in the International System of Units (SI). It denotes a rate of energy transfer of 100 joules per second. A watt is equal to 1/1000 of a kilowatt, so 100 W equals 0.1 kW. The watt is named after James Watt, an 18th-century inventor.

In consumer electronics and household devices, "100 W" commonly indicates the nominal power consumption or output. For lighting, a traditional incandescent bulb labeled 100 W consumes about 100 watts and emits roughly 1,600 lumens; modern light sources (LEDs) deliver similar brightness at far lower power (roughly 15–20 W for comparable luminous flux).

In audio equipment, a 100 W specification usually refers to continuous (RMS) output power into a given impedance (often 8 ohms) rather than peak power. Real-world performance depends on efficiency and distortion; many amplifiers advertise higher peak values that are not sustainable.

For photovoltaic systems, a panel rated at 100 W is designed to produce around 100 W of electrical power under standardized test conditions, typically around 1000 watts per square meter of sunlight. Actual output varies with sun angle, temperature, shading, and age.

100 W can be converted to other units: 100 W equals 0.1 kilowatts or 100 joules per second. In practical terms, it is a common size for small home devices such as space heaters or chargers, but efficiency differences mean energy consumption over time depends on usage.