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Lumens to Watts Calculator

Lumens is used to measure the total amount of visible light from any light source. SI unit of luminous flux is called as the lumens. The more the brighter the light looks the more the lumen rating is. While watt measures the total light power, lumen measures the human eyes visible light power. One luman is equal to 1/683 of watt light power.

Convert lm to w

lm
lm/W
W

Lumens is used to measure the total amount of visible light from any light source. SI unit of luminous flux is called as the lumens. The more the brighter the light looks the more the lumen rating is. While watt measures the total light power, lumen measures the human eyes visible light power. One luman is equal to 1/683 of watt light power.

Formula:

P = φv / η Where, P = Power φv = Luminous Flux η = Luminous Efficacy

European union has made it mandatory for all lighting equipment to be labelled primarily in terms of luminous flux (lm) instead of Watts. This is an online converter to convert the lumens to watts based on luminous efficacy.

Example

Lumens to Watts

If you want to convert f 40 lm of an LED with 20 luminous efficacy into watts,
W = 40 / 20
W = 2