Lux (lx)
The lux (lx) is the SI unit of illuminance: one lumen falling on each square metre. Offices are lit to about 300–500 lx; direct sunlight gives up to 100,000 lx.
Symbol: lx
Quantity: illuminance (light falling on a surface)
SI relation: lx is the coherent SI unit of illuminance.
Derivation: 1 lx = 1 lm/m².
Exact: yes, by definition
Typical uses
- Workplace lighting standards (EN 12464)
- Light meters and photography
- Plant growing
Convert lux to other units
| Conversion | 1 lx equals | Reverse |
|---|---|---|
| lux to foot-candle | 0.09290304 fc | foot-candle to lux |
| lux to kilolux | 0.001 klx | kilolux to lux |
| lux to phot | 0.0001 ph | phot to lux |
| lux to millilux | 1000 mlx | millilux to lux |
Open the Illuminance Converter (Lux, Foot-candle) to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (becquerel, gray, sievert, lux) and Table 2 (candela).
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Lux (lx). Retrieved October 25, 2026, from https://scientificconverters.com/units/lux/
IEEE
Scientific Converters, "Lux (lx)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/units/lux/