Illuminance Units

This illuminance converter converts between lux (lumens per square meter), foot-candles (lumens per square foot), and the derived units phot and nox. The relationship is exact: 1 fc = 10.76391 lx, since one square foot equals 0.092903 m².

Lighting Standards

Workplace standards specify illuminance targets — typically 300–500 lux for offices, 750 lux for fine detail work, and 50–100 lux for corridors. Converting spec sheets between US foot-candles and international lux is a daily task for lighting designers.

Lux vs Lumens

Lumens measure the total light a source emits; lux measures how concentrated that light is on a surface. The same 1,000-lumen bulb delivers far fewer lux at 4 meters than at 1 meter — which is why distance always matters in lighting math.