Lux and foot-candles are units used to measure illuminance, indicating how much light reaches a surface. Lux measures illuminance in lumens per square meter, while foot-candles measure it in lumens per square foot. To convert lux to foot-candles, divide the lux value by 10.76391. For example, 100 lux is approximately equal to 9.29 foot-candles. Conversely, to convert foot-candles to lux, multiply the foot-candle value by 10.76391. Accurate conversion between these units is essential for lighting professionals to ensure appropriate illumination levels in various settings.