Lighting Calculations is the best app in the field of lighting, it has lots of calculations that can help you in your work. It can not miss in your smartphone! Calculation of total flux [PRO]. Lighting requirements for interiors. Quantity of luminaires. Lumens to Lux. Lux to Lumens. Lumens to Watts. Watts to Lumens. Lux to Watts. Watts to Lux. Lumens to Candela.