illuminance · International · Modern
1 lx = 1 lm/m²
Converter
illuminance · US / international technical use · Modern/historical
foot-candle
exact
- Record
- M333
- Definition quality
- Standardized
- Conversion mode
- multiplicative
- Calculator
- Fully calculable
Definition
1 fc = 1 lm/ft² ≈ 10.76391 lx
Reference value
One foot-candle is exactly 10.76391 lux.
History & use
It belongs to the foot-based photometric system used alongside SI lighting units; NIST calibration literature defines it as lumen per square foot.
Modern use
Modern use is context-dependent and varies by region or measurement system.