How bright is a light bulb? Lumens Vs. Watts

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This 5W LED from WholesaleLED.com has
400 lumens of light.
That's more than a 40 Watt Bulb
There seems to be some confusion about how to tell how bright a light bulb really is. It was easy enough when we all used incandescent lights. You could choose from a 40, 60, 75 or 100 watt bulb, and we all have a rough idea of how bright that will be.

When you begin to get into new lighting solutions like CFLs and LEDs, using the wattage doesn’t work very well any more. Now you have 20 watt CFLs, and 12 watt LEDs and no idea what's going to keep you from going blind while reading. Well, read on and learn how to tell how bright something actually is. Before you lose your eyesight.


Just Look to the Lumens

To understand this, it's important to know the difference in lumens Vs watts. A Lumen is standard unit of light as it is perceived by the human eye. Essentially, it will tell you how bright something is, unlike a watt, which is actually a measurement of energy consumption or output. The lighting industry has standardized ways that it measures the total emission of light from a product and include it on most packaging. Here’s the lumens from some everyday objects to give you a better idea.

  • 40 watt incandescent = 380 – 460 Lumens
  • 60 watt incandescent = 750 – 850 lumens
  • 75 watt incandescent = 1100 – 1300 lumens
  • 100 watt incandescent = 1700 – 1800 lumens
  • Direct sunlight = 100,000 lumens.

One of the reason LEDs are so attractive is that with a fraction of the power use (watts) you can get the same amount of light (lumens) as an incandescent.


You can get as many as 110 lumens per watt with an LED bulb. Compare that to an incandescent, which only produces 12-17 lumens per watt. Now that’s some science that can save you money.

Check out some of our other articles if you want to learn more about how an LED light bulb works.



- Posting from: http://blog.nularis.com/2011/05/how-bright-is-light-bulb-lumens-vs.html