Lumens per Watt Calculator
Calculate the luminous efficacy of a light source by dividing its light output by its power consumption.
lumens
watts
Luminous Efficacy
80.0 lm/W
Annual Energy Cost (8hr/day)$4.38
Luminous Efficacy
Efficacy = Lumens / Watts
Higher efficacy means more light per unit of energy.
Efficacy Benchmarks
Example Calculation
800 lumens from a 10 watt LED.
- 01Efficacy = 800 / 10 = 80 lm/W
- 02Annual cost at 8hr/day: 10W x 8 x 365 / 1000 x $0.15 = $4.38
Frequently Asked Questions
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