4 units
Illuminance Converter
Convert lux, foot-candles and phot.
About illuminance units
Illuminance is how much light falls on a surface. One lux is one lumen per square metre; one foot-candle is one lumen per square foot, about 10.76 lux. These units describe the light received by a surface, rather than the output of a lamp.
Illuminance is luminous flux arriving per surface area: 1 lx = 1 lm/m². Converting lux to lumens requires an area and a model of how the light is distributed.
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All units
Compare unit values in the base unit. Numbers are rounded to 8 significant digits; conventions and assumptions appear beside the units.
| Unit | Symbol | 1 unit in lx |
|---|---|---|
| lux | lx | 1 |
| foot-candle | fc | 10.76391 |
| phot | ph | 10,000 |
| kilolux | klx | 1,000 |
All conversion pages
Each page has the formula, worked examples and a reference table.