Convert foot-candle [ft*c, fc] to lumen/square meter [lm/m^2] Online | Free lllumination Converter

A Unit of Illuminance

The foot-candle (ft·c or fc) is a unit of illuminance used primarily in the United States and some other countries that follow imperial measurements. It measures the amount of luminous flux (light) falling on a surface of one square foot. One foot-candle is defined as one lumen per square foot.

Foot-candles are commonly used in lighting design, architecture, photography, and workplace safety to ensure spaces have appropriate lighting levels. For example, an office workspace typically requires around 30 to 50 foot-candles to provide sufficient brightness for tasks without causing eye strain. Retail stores and hospitals may require higher levels, while hallways or staircases might have lower standards.

Foot-candles are related to the metric unit lux, where 1 foot-candle equals approximately 10.76 lux (lumens per square meter). Understanding foot-candle measurements allows designers and engineers to plan lighting layouts effectively, balancing energy use with visual comfort.

Despite the growing global adoption of the lux, foot-candles remain prevalent in industries and regions that use imperial units, making it important for professionals to be familiar with both.

The Standard Unit of Illuminance

Lumen per square meter (lm/m²), also known as lux, is the standard unit used to measure illuminance, which is the amount of luminous flux (light) falling on a surface per unit area. One lux equals one lumen distributed over one square meter, quantifying how brightly a surface is illuminated.

Lux is widely used in lighting design, architecture, photography, and occupational health to ensure proper lighting conditions for various environments. For instance, office spaces typically require around 300-500 lux to provide comfortable and efficient lighting for work, while outdoor daylight can range from 10,000 to over 100,000 lux.

Understanding illuminance in lux helps in designing lighting systems that optimize visibility, safety, and energy consumption. It allows engineers and designers to calculate how much light a space receives and adjust fixtures or bulbs accordingly.

Lux is preferred globally because it aligns with the metric system and provides a clear, standardized measure of light intensity on surfaces, making it essential for ensuring consistent and effective lighting in both indoor and outdoor settings.