The quantity of light is measured in multiple ways. Lumens and footcandles are two commonly used measures that also tend to be the most confusing. Understanding the difference can help you decide what type of light to use and how much you need for a space. Let’s shed a little light on the matter.

Lumens measure the light output from a source. The higher the lumen number, the more light a fixture gives off. But, a 10,000 lumen fixture is always a 10,000 lumen fixture. No matter whether you put it in a small room or a parking lot, it’s always 10,000 lumens.

Footcandles measure how much light is hitting a surface. This is more important when you’re deciding how much light you need because it takes the space into account. Unlike lumens, footcandles can change depending on distance from the light source, wall reflectance, objects in the way and more.

So, a 10,000 lumen fixture in a small room is probably going to be very bright, while the same fixture placed high above a parking lot may not be bright enough. While lumens help you achieve the footcandle readings you’re looking for, footcandle measurements can help you choose the right lights, design them with the right spacing and create the perfect lighting for your application.