When dealing with lighting, there are two concepts used to determine lighting power consumption and brightness: a light bulb’s wattage and lumen output. These concepts have been confused in recent years, and some misconceptions have come up as a result. There is a difference between watt and lumen—one more accurately measures light output than the other.
The Old Standard of Measurement: Watts
In the past, the traditional method in which companies advertised the light output of their light bulbs was through wattage. A watt measures the rate of energy transfer and is typically one joule per second. With incandescent light bulbs, the more wattage that the bulb used, the brighter the light would be as a result.
How More Watts Equaled More Light
The thinking back then was that the more energy an incandescent light bulb consumed, then the brighter the bulb. Watts do not and have never measured light output; they only measured energy consumption. It was true back then that more watts equaled more light, but that is not the case today.
Lumens and How They Compare To Watts
A lumen is a standard unit of measurement for the amount of visible light that a light source emits. Unlike watts, lumens are a direct and reliable way to measure the amount of light a bulb generates.
Why Watts No Longer Equal More Light?
With the increased popularity of LED light bulbs, the mainstream terminology was slower to catch on. The science behind LED light bulbs is that they consume less electricity than older incandescent bulbs, meaning that they have a lower wattage.
This translates to if you had a linear LED light fixture that generated 7,200 lumens, then it only consumes roughly 60 watts. This is in contrast to an incandescent bulb that generates 850 lumens while using 60 watts. The light output is more than eight times brighter with LEDs yet uses the same number of watts as the incandescent.
The New Standard of Measurement
The difference between watt and lumen is night and day. With the rise of energy-efficient bulbs, energy consumption no longer equates to light output. With far less wattage, new LED lights can generate far more brightness.