Illuminance Converter — Lux, Foot-candle, Phot
The Illuminance Converter converts between all major illuminance units — lux, foot-candles, phot, and nox. Illuminance measures how much light falls on a surface and is used in photography, architectural lighting design, horticulture, workplace safety standards, and display calibration. This free converter handles every illuminance unit instantly.
How to Use This Calculator
- 1
Enter the illuminance value you want to convert.
- 2
Select the unit you are converting from (e.g. Lux).
- 3
Select the target unit (e.g. Foot-candle).
- 4
Click Convert to see the result.
Frequently Asked Questions
Lux (lx) is the SI unit of illuminance — it measures how much luminous flux falls on one square metre of surface. 1 lux = 1 lumen per square metre. Direct sunlight is about 100,000 lux; a well-lit office is 300–500 lux; moonlight is about 1 lux.