Converters · NUMORA
Lumens To Watts Calculator
W = lm / (lm/W). Efficacy is an input; there is no single factor.
Open interactive calculatorHow to use
Lumens are luminous flux; watts are electrical power. Efficacy bridges them.
Formula
W = lm / η, with η in lm/W
FAQ
Is this Lumens To Watts calculator accurate?
The formula and assumptions are shown on the page, and the engine is covered by audit tests. Results are for reference — not financial or medical advice.
Do I need an account?
No. Calculations run in your browser. Recents can stay on this device.
What inputs do I need?
Lumens are luminous flux; watts are electrical power. Efficacy bridges them.
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