What Does Lux Mean?

When you want to know how much light a particular light source emits, you often look at the number of lumens listed on the lamp. However, this does not mean you can directly deduce how much light from the lamp falls on, for example, your desk or workspace. This is not measured in lumens, but in lux.

What is Lux?

Lux is simply the amount of light that falls on a surface. To be more specific: lux is the number of lumens (the light emitted by the lamp) per square meter, and is therefore expressed in lm/m­­². The number of lux is affected by the distance between the light source and the surface being measured. Logically, more light falls on a surface that is 1 meter away from the light source than on a surface that is 5 meters away. Think of a reading lamp you switch on in the evening: under the lamp, you can read your book well because the lux values are high there. But if you sit further away from the lamp, the book becomes almost unreadable. The number of lumens from the lamp is still the same, but the number of lux on the pages of your book has decreased.

What are Common Lux Values?

Of course, there are guidelines to assess whether the lux values in a space are sufficient. For example, offices typically have lux values of around 300-500lx. For comparison, indirect sunlight has a value of about 10,000 lux, and a living room often only has about 50 lux. The necessary lux value largely depends on the function of the space.

When Are Lux Values Important?

Lux values are important when you want to assess whether a surface or workspace is sufficiently illuminated or when creating a lighting plan. Naturally, the brightness of the light source is related to this, but it’s also important to look at the placement of the light source. This greatly influences the number of lux on a surface. When we at Qub create a lighting plan, we consider not only the number of lumens from the lamp but mainly focus on the lux values on different surfaces.

Want to learn more about lux values? Or would you like advice on the lighting for a space? Feel free to contact us. The team of Qub lighting experts is happy to assist you!