How bright is an LED light bulb – Hint: look at Lumens not watts

How to Tell How Bright a Light Bulb Is

One of the most common questions we get is how to tell how bright a LED light bulb really is. Most of our customers have a pretty good idea of what a 40, 60, or 75 watt incandescent looks like, but have no idea what a 4 watt LED light bulb would look when compared to 40 watt incandescent.

Adding to the confusion is the fact that LED lights can come with various levels of efficiency, meaning that one 9 watt LED light may actually be just as bright as a 12 watt LED.

Throw in CFL lights with wattages between 10- and 25 watts, and you begin to realize watts don’t mean what they used to.

That’s why we created this guide to help you tell how bright a light bulb really is.

Understanding Lumens

Lumens are a way of measuring light. Essentially the higher the lumen count the brighter the bulb. The table below will help you get an idea of how many lumens are in the incandescent lights that are familiar to most people.

·       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.

If you divide the number of lumens by the number of watts used you can tell how many lumens per watt the particular light is using.

So for example:
40 watt incandescent = 460 lumens/40 watts = 11.5 lumens for each watt of electricity used.

Most incandescent and halogen lights get between 11 and 18 lumens of light for each watt consumed.

So how bright are LED lights?

Here is an example of the lumen output of a typical LED light from

·       Average 7 watt LED light = 660 - 750 Lumens
·       Average 9 watt LED light = 800 - 900  lumens
·       Average 12 watt LED = 900 – 1200

Again we can divide the number of lumens by watts to tell how efficient a particular LED light is.

For example:
460 lumens/7 watts = 65.7 lumens for each watt of electricity used.

Keep in mind this is just an example, and many newer LED lights can actually emit as much as 110 lumens per watt, though a typical LED on the market now is between 65 and 90 lumens per watt.

You can see how widely the light output varies depending on the efficiency of any given bulb. That’s why your best bet is to take a look at the lumens on any given LED light and compare it to the chart of incandescent lights listed above. 

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