Difference between Lumens, Lumen Flux and Lamp Lumens

What is the difference between lumens flux and lamp lumens? On lighting cutsheets you don’t always see lumens but lumens flux instead, can we use lumens flux in place of lumens on lighting calculations?


I am so happy that you posted this to the PPD community page. In photometry, luminous flux is the measure of the perceived power of light. Luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. The SI unit of luminous flux is the lumen (lm). In other systems of units, luminous flux may have units of power. So for the purposes of the the ARE if you see luminous flux it is most likely going to be in lumens. I hope that this helps.

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