Illumination Converter

Convert light intensity units — lux, kilolux, foot-candles and phot.

Convert illumination units

Illuminance measures how much light falls on a surface. This converter switches between the metric unit lux (lumens per square metre), kilolux, the imperial foot-candle (lumens per square foot), and the CGS unit phot. It is useful for lighting design, photography, horticulture, and workplace safety standards.

Typical light levels

EnvironmentApprox. illuminance
Moonlight~1 lux
Living room50–150 lux
Office / classroom300–500 lux
Overcast daylight~1,000 lux
Direct sunlight32,000–100,000 lux

Frequently asked questions

How many lux in a foot-candle?

One foot-candle equals about 10.764 lux.

What is the difference between lux and lumens?

Lumens measure the total light a source emits; lux measures how much of that light lands on a surface. One lux equals one lumen spread over one square metre.