What is a Footcandle & How is it Used in Lighting?

In the field of lighting, there are a lot of terms to understand. While most people have a pretty good grasp of concepts such as lumen output, wattages consumed, or color temperature, the matter of a footcandle is often a confusing topic. So, what is a footcandle and how is it used in lighting? Let’s take a closer look at this matter and the role it plays in determining appropriate lighting solutions.

What is a footcandle?

A simple definition is that a footcandle is a unit of measure used to measure light. However, there is more to the concept than that simple explanation. A footcandle has been around since before electricity was even discovered. When people would light a candle for illumination, they soon decided there was a need to create a standard candle size as a guideline in relation to how much illumination could be provided to a space. This measurement would go on to be called a footcandle because it represented the typical measure of light provided by a single source of illumination.

How is a footcandle used in lighting?

While lumens are often seen as the most important factor to consider when choosing lighting, the matter of a footcandle is also important to finding the right solution. A footcandle is now used as a measure which indicates one lumen per square foot of space. When looking at the matter of lumens, lighting is often chosen based on the lumen output compared to wattage of energy consumed to create that lumen output. While this is an important figure, a footcandle is also essential because it helps you to figure exactly how many lumens you need per square foot. For example, if you are looking to light a space of 100 feet, you will need at least 100 footcandle units to achieve the right illumination for the space.

What is the main difference between lumen and footcandle?

While the two terms are closely related to one another, they mean different things. A lumen measures how much illumination comes out of the lamp. The footcandle measures how much illumination reaches the standard of a foot away from the lamp source. To find the best solution, both figures should be taken into consideration when choosing lighting applications for any given space.