Enter the luminous flux in lumens, luminous efficacy in lumens per watt and press the Calculate button to get the power in watts:
* the predefined luminous efficacy values are typical / average values.
Lumens to watts calculation formula
Energy saving lamps have high luminous efficacy (more lumens per watt).
The power P in watts (W) is equal to the luminous flux ΦV in lumens (lm), divided by the luminous efficacy η in lumens per watt (lm/W):
P(W) = ΦV(lm) / η(lm/W)
Lumens to watts table
|375 lm||25 W||6.23 W|
|600 lm||40 W||10 W|
|900 lm||60 W||15 W|
|1125 lm||75 W||18.75 W|
|1500 lm||100 W||25 W|
|2250 lm||150 W||37.5 W|
|3000 lm||200 W||50 W|