Illuminance units measuring luminous flux incident on a surface. Lumen and candela are different photometric quantities and are not directly converted here.
All factors come from the central conversion registry.
| Unit | Symbol | System | Definition |
|---|---|---|---|
| Lux | lx | SI | 1 lx = 1 lm/m² |
| Kilolux | klx | SI | 1 klx = 1000 lx |
| Foot-candle | fc | US customary lighting | 1 fc = 10.7639104167097 lx |
| Phot | ph | CGS | 1 ph = 10,000 lx |
Illuminance units measuring luminous flux incident on a surface. Lumen and candela are different photometric quantities and are not directly converted here.
The interactive calculator, reference table and indexed pair pages all read from the same conversion registry, so unit definitions and formulas stay synchronized.