Convert Watts to Lumens​
Converting Watts to Lumen is necessary if you are going to replace an incandescent or halogen lamp with an LED lamp. The number of watts only indicates how much energy an incandescent or halogen lamp uses, while you would actually rather know how much light the lamp actually emits, because that is what it is all about. This light output is expressed in lumens.
For example, a 40-watt incandescent lamp has a light output of approximately 450 lumens. For the same light output, you only need a 6-watt LED lamp! With the table below you can easily convert Watts to Lumen and vice versa.
Note: Keep in mind that this table is a guideline and that there may be differences per brand.
In the table above you can see that you only need a 4 Watt LED lamp to replace a 25 Watt incandescent lamp to obtain the same light output.
The specifications of an LED lamp state the number of lumens, for example 250 lumens. Is the number of lumens not listed? Then look at the stated luminous flux, expressed in lumens/Watt. Multiply this number by the number of Watts to calculate the number of lumens.
The formula is: Lumen (lm) = luminous flux (lm/W) x power (W)
In the example of 250 lumens that we just mentioned, the calculation would be: 135 (lm/W) x 6 (Watt) = 810 lumens.
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Common lumens counts​
Want to know what a specific number of lumens in watts is?
Below are the most requested ratios:
​Number of lumens per room in the house:
