Illuminance Converter
Convert between all illuminance units instantly. Select your units from the dropdowns below and enter a value to see the conversion in real-time.
SI unit: lux (lx)
Conversion Formula
Select units to see the conversion formula.
About Illuminance Units
Select units above to see detailed information about them.
Common Illuminance Conversions
- 1 lx = 1 lm/m² (SI definition)
- 1 fc (foot-candle) = 1 lm/ft² ≈ 10.764 lx
- 1 ph (phot) = 1 lm/cm² = 10 000 lx (CGS unit)
- 1 mlx = 1 nox (CIE historical unit; exact equivalence)
- Moonless clear night sky: ~1 mlx; full moon at zenith: ~100-270 mlx
- Typical office (EN 12464-1): 300-500 lx
- Direct mid-latitude sunlight at noon: ~80-100 klx
- IESNA general office recommendation: 30-50 fc (≈ 320-540 lx)
- SMPTE cinema screen standard: 12-16 fc (≈ 130-172 lx)
- Point source inverse-square law: E = I / r² (I in cd, r in m, E in lx)