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

## Watts to lux calculation :-

#### 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 (ft^{2}):

*E*_{v(lx)} = 10.76391 × *P*_{(W)} × *η*_{(lm/W)} / *A*_{(ft}2_{)}

#### 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 (m^{2}):

*E*_{v(lx)} = *P*_{(W)} × *η*_{(lm/W)} / *A*_{(m}2_{)}