Watts to lux

It is used to convert the electric power in watt (W) to illuminance in lux (lx). It has four text fields and options of executing the conversion. The watts to lux calculator also has two controls, ‘Calculate’ and ‘Reset’ buttons which operate independently performing different functions of the calculator. The first step is to enter the value of power in watts.

Select the light source in the options provided by the calculator. If you do not find the particular appliance, you will manually enter the value of luminous efficacy in lumens per watt. The next step is to enter the surface are or the spherical radius and then click the ‘Calculate’ button to initiate the process of conversion. Your results are displayed within a single click in the bottom platform of the calculator below the two controls.

For example;

Determine the illuminance in lux of a LED lamp having 240 watts and a surface area of 1000 square feet.

Watts to lux calculation formula

Watts to lux calculation with area in square feet

The illuminance E_v in lux (lx) is equal to 10.76391 times the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W) divided by the surface area A in square feet (ft²):

E_v(lx) = 10.76391 × P_(W) × η_(lm/W) / A_(ft2₎

Watts to lux calculation with area in square meters

The illuminance E_v in lux (lx) is equal to the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W) divided by the surface area A in square meters (m²):

E_v(lx) = P_(W) × η_(lm/W) / A_(m2₎