Illuminance Converter
Convert between 7 units of illuminance — lux, millilux, kilolux, footcandle, phot, lm/m², and lm/ft².
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About the Illuminance Converter
Illuminance measures the amount of luminous flux (visible light) falling on a unit area of surface — essentially how brightly a surface is lit. The SI unit is the lux (lx), defined as one lumen per square metre. The footcandle (fc) is still used in US lighting design and photography. Proper illuminance levels are specified by standards for workplaces, roads, sports facilities, and emergency lighting to ensure safety and productivity.
Quick facts
- ›Direct sunlight provides about 100,000 lux; an overcast sky gives 1,000–10,000 lux
- ›Office lighting standards recommend 300–500 lux at desk level
- ›A full moon provides only about 0.25 lux — making reading difficult outdoors at night
- ›One footcandle = 10.764 lux (the footcandle measures lumens per square foot)
Common uses: Architectural lighting, workplace safety, photography, horticulture, road lighting, displays