Watts to lux (lx) conversion calculator

Enter the power in watts, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the Calculate button to get the illuminance in lux:


Enter power in watts:
	W
Select light source

Or enter luminous efficacy in lumens per watt:
	lm/W
Enter surface area:

Or enter spherical radius:




Illuminance result in lux:
	lx

Lux to watts calculator ►

* the predefined luminous efficacy values are typical / average values.

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₎

Watts to lux calculation ►

Watts to lux calculator

Watts to lux calculation formula

Watts to lux calculation with area in square feet

Watts to lux calculation with area in square meters

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