The invention of the incandescent lamp brought with it the standard for measuring the brightness of bulbs: the Watt. The Watt is a unit of power and was used as the benchmark in the belief that the consumption of power was proposal to the output of light.
For many years this formula has worked relatively well. For the most part, 100W bulbs developed by different manufacturers emitted more or less the same light. This went for 60W and 40W bulbs too.
When LED light bulbs became more popular in the market the model began to show some flaws. Today a 6W LED bulb is capable of generating the same kind of brightness as a filament bulb of 60W, and it’s obvious that you can’t even compare the two.
It is true that more modern bulbs can be compared to traditional incandescent lights when it comes to their wattage. If you purchase an LED right now, the outside package will tell you very clearly what wattage of light it is designed to replace. This is to make replacements easier for people who are accustomed to using traditional lamps.
A rough guide is that the ratio generally comes out at 10% but as LEDs are manufactured more efficiently this figure is likely to go down.
Because of this it has been necessary to develop a standard for light emission. And that’s where the lumen has come in.
The lumen is the metric used to measure the efficacy of LED light bulbs. lumens demonstrate an LED bulb’s light output, instead of the energy it uses to generate that light. Because of this it’s a much more accurate way of measuring it.
If you were to compare the light output of the 6W and 60W bulbs, you would find the lumens would match. Wattage is still a common way for people to gauge brightness but it is no longer the most accurate way available.