Illumination Converter

About This Tool

This Illuminance Converter is a tool for lighting designers, architects, photographers, and anyone involved in assessing light levels. It converts units of illuminance, which is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface. The base unit is the lux (lx).

Illuminance is what you measure with a light meter. It tells you how much light is falling on a specific area, regardless of the color or nature of that surface. It is crucial for designing spaces that are well-lit for specific tasks (e.g., offices, workshops) and for setting up lighting for photography and videography.

Tips & Features

• Lux and Lumens: The lux is the SI unit, defined as one lumen per square meter (lm/m²). It directly relates the total light output (lumens) of a source to the area it is spread over.
• Foot-candle (fc): The foot-candle is the corresponding imperial/U.S. customary unit, equal to one lumen per square foot. Since a square meter is larger than a square foot, 1 foot-candle is about 10.76 lux. A common rule of thumb is to approximate 1 fc ≈ 10 lux.
• Illuminance vs. Luminance: Remember, illuminance is the cause (light arriving), while luminance is the effect (light leaving, i.e., the perceived brightness). A light meter measures illuminance.