Therefore watts is no longer as relevant in making a buying decision with today’s LED lights. Yet, it is clear that Watts is no longer the indicator of light brightness that is used to be. Power consumption (Watts) is always an important factor in lighting. LED bulbs are the most energy-efficient of those shown above using less than ¼ of the energy of an incandescent bulb. Notice that the Light-emitting Diode (LED) bulb emits 1,600 lumens using only 22 watts. You can see the variability between Watts and Lumens based on different light source types. To illustrate the difference in bulb types, each of these bulbs emit roughly 1600 Lumens: Measuring brightness by Lumens takes the bulb type out of the equation and focuses only on the brightness of the bulb or emitter. More Watts meant a brighter bulb and more light output in a way that the average person could understand.ĭifferent light sources such as incandescent, halogen, fluorescent, LED and others produce light at different energy efficiencies. When the light bulb materials are consistent, the variable in brightness becomes the amount of power behind the bulb. So what is the deal with watts advertised on household light bulbs? When incandescent bulbs were the mainstay of lighting across the land, the same or similar materials were used in their manufacture. More info on Watts can be found in this video.

We learned before that Lumens is a measurement of total light output, but there is no mention of light in the equation above. There is no easy conversion between Watts and Lumens without taking into account the light source. Clearly Watts and Lumens really don’t measure the same thing. Lumens is a measurement of light output while Watts is a measurement of power or energy consumption over time. Lumens is the measure of the total light output from a light source in all directions. Lumens have replaced watts as the most advertised feature of today’s light bulbs. If you want to focus on the overall brightness of a light, your material concern is Lumens.

One Lumen is equal to one Candela of light at a distance of one meter from the light source, and we’ll see how that is measured further down. Lumens is a measure of the total output from a light source in all directions. Wait…did I type that out loud? What Does Lumens Measure? What are Lumens? Lumens (lm), by definition, is a marketing term that is often misused to indicate flashlight quality. Let’s break each of these down to better understand them. Like lumen, the Latin word lux also means light. Another adaptation of a Latin word, lux emerged in English around the same time. It was an adaptation of the Latin word lumen, which translates to English as light. Use of the English word Lumen as a measure of light began in the late 1800s – more than 20 years after the coinage of the word candlepower. In 1948, the definition was changed to reference platinum and radiometry instead of whale wax and grains, and the term candlepower was replaced with Candela. Between 18, a unit of candlepower was measured from a candle that was made from pure spermaceti (wax from sperm whales), weighed one-sixth of one pound, and burned at 120 grains per hour. The term candlepower – now mostly obsolete – was coined in 1869 according to Merriam-webster, and refers to a unit of luminous intensity. The history of Candela goes back 150 years. Lux measures the amount of light that falls on a surface.Ĭandela is light’s intensity as visible to the human eye in a specific direction. Lumens is a measurement of how much light is emitted from a light source in all directions. What’s the difference between Lumens, Lux, and Candela? How do Lumens, Candela, and Lux relate to each other?.What’s the difference between Lumens, Lux, and Candela?.

Candela meaning