Question 1

How efficient are different light bulbs?

Accepted Answer

Incandescent: 10-17 lumens/watt. Halogen: 15-25 lm/W. CFL: 50-70 lm/W. LED: 80-150+ lm/W. LED is 8-10× more efficient than incandescent.

Question 2

Why do LED wattages seem low?

Accepted Answer

LED efficiency is much higher. A 10W LED produces 800 lumens (same as 60W incandescent). Always compare lumens, not watts, when choosing bulbs.

Question 3

What's the difference between lumens and lux?

Accepted Answer

Lumens measure total light output from a source. Lux measures light arriving at a surface. Same lumens in a smaller area = higher lux.

Question 4

How do I convert old wattage to lumens?

Accepted Answer

Roughly: 40W incandescent ≈ 450 lumens, 60W ≈ 800 lumens, 100W ≈ 1600 lumens. LED equivalents use 80-90% less power for same lumens.

lm to W Converter

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