Illuminance Converter
Convert lux, foot-candles, phot and more.
How to use
- 1 Enter the illuminance value you have.
- 2 Select the unit that value is measured in.
- 3 Read the equivalent in every other unit.
- 4 Copy the full conversion list if you need it.
About Illuminance Converter
The Illuminance Converter translates a light level from one unit into every other common unit at once.
Illuminance describes how much luminous flux lands on a surface per unit area, and it is the number you reach for when checking whether a workspace, a film set, a greenhouse or a camera scene is bright enough.
The SI unit is the lux, equal to one lumen per square metre, and every conversion here pivots through lux for accuracy.
Supported units include lux and its identical twin lumen-per-square-metre, the imperial foot-candle (one lumen per square foot, about 10.764 lux), the CGS phot (one lumen per square centimetre, exactly 10 000 lux), the kilolux for very bright daylight readings, and the nox, an old unit equal to one millilux used for very dim conditions.
Type a value, choose the unit it is in, and the full set of equivalents appears instantly.
It is handy for translating a lighting-design spec quoted in foot-candles into the lux figure your light meter shows, or for sizing fixtures against a target illuminance.
Everything is computed locally in your browser with standard conversion factors — no data leaves your device — so it is fast, private and works offline.
FAQ
How many lux is one foot-candle?
One foot-candle equals roughly 10.764 lux, because it is one lumen spread over a square foot rather than a square metre. The converter uses the exact factor for precision.
What is the difference between lux and lumens?
Lumens measure the total light a source emits, while lux measures how much of that light reaches a surface per square metre. Lux therefore depends on both the source and the distance.