Common levels for indoor illumination typically range between 200 to 500 lux, but may be as low as 25 lux in many commercial buildings. 300 to 500 lux is typically sufficient for casual reading, but light levels between 500 to 1200 lux are commonly found in supermarkets and workshop environments.
A lux is a unit of illumination that equals one lumen per square meter. To obtain specific levels of illumination, standardized commercially-designed light fixtures and fittings must be used. Office environments and areas where computer displays and other light-emitting devices are utilized should make use of indirect or deep-cell parabolic ceiling fixtures that provide diffuse illumination.