About this tool
Convert a lighting illuminance value between five units, entirely in your browser with no upload. Pick the From and To units, type a value, and the result updates live; the ⇄ button swaps the two units.
The base unit is the lux (lx), which is one lumen per square metre — so lux and lm/m² are identical here. Each unit carries an exact factor to lux: one foot-candle equals 10.76391 lux (one lumen per square foot), one phot equals 10,000 lux (the bright CGS unit, one lumen per square centimetre), and one nox is 0.001 lux for very dim levels. For example 1 foot-candle converts to 10.764 lux.
Handy for photography and film lighting, workspace and office lighting standards, greenhouse and grow-room planning, and photometry. Note that illuminance measures light falling on a surface — it is different from luminance (brightness of a surface) and from colour temperature in kelvin.