Illuminance in lux (lx) to 電気 power in watts (W) 計算機 and how to 計算.
Enter the illuminance in lux, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the 計算 button to get the power in watts:
* the predefined luminous efficacy values are typical / average values.
The power P in watts (W) is equal to the 0.09290304 times the illuminance Ev in lux (lx) times the surface area A in square feet (ft2), divided by the luminous efficacy η in lumens per watt (lm/W):
P(W) = 0.09290304 × Ev(lx) × A(ft2) / η(lm/W)
The power P in watts (W) is equal to the illuminance Ev in lux (lx) times the surface area A in square meters (m2), divided by the luminous efficacy η in lumens per watt (lm/W):
P(W) = Ev(lx) × A(m2) / η(lm/W)