SI unit of measurement

Definition of Watt

Watt is the standard unit of measurement used to quantify the amount of energy a light bulb uses to generate light. One watt is equivalent to one joule of energy consumed every second.

The watt unit is named after James Watt, a Scottish mechanical engineer who developed steam engine technology.

All light bulbs have a power rating, measured in watts (W). The higher the wattage, the greater the electrical consumption of the bulb.

In the past, when incandescent light bulbs were more prevalent, the wattage of a light bulb determined its brightness. It was generally accepted that the higher the bulb’s wattage, the brighter the light source was.

However, new lighting technologies, such as light-emitting diodes (LEDs) and compact fluorescent lamps (CFLs), are now more efficient than incandescent lamps, as they use less energy yet still emit a similar or better light output.

For example, the 6” LED ceiling light has an output of 350 lumens and a wattage of 9.3 W. It takes 40 W for an incandescent lamp to generate a similar brightness level. As such, lumens are now the reliable way to measure the brightness of a fixture.

watt comparison chart

LED lights are a good choice for marine lighting since they emit very little heat and are the most efficient lights compared to CFLs, halogen, and incandescent bulbs.

You can find a wide variety of marine LED lights for both your outdoor and indoor lighting at the Apex Lighting store, including:

  • Navigation lights
  • Underwater lights
  • Dock lights
  • Reading lights

Example of Watt in a Sentence

"A light bulb that uses 60 watts consumes more energy than one that uses 40 watts. "

Related Terms for Watt