Illuminance Converter
A precise tool to convert between various illuminance units like Lux, Foot-candles, and Phots.
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About this tool
Convert illuminance, the amount of light falling on a surface, between lux (lx), foot-candle (fc), phot (ph), nox (nx), meter-candle (mc), lumen per square centimeter (lm/cm²) and lumen per square millimeter (lm/mm²). The menus show full names with symbols, and the result is labeled with the symbol. Lux is the SI unit and the one most light meters and building standards use in Europe; foot-candles are common in the US, where 1 foot-candle is about 10.764 lux. A meter-candle is identical to a lux. Conversions pass through lux. Results show up to 8 decimals. This is about light on a surface, not a lamp's total output in lumens.
How to use it
- Type the value to convert.
- Choose the From and To units.
- Read the result, which updates as you type.
- Use Swap to reverse the units or Copy to copy the result.
Example
A common office lighting level.
500 lux to foot-candle
46.45152 fc
Common problems
- Lumens vs lux
- Lumens measure total light output of a source. Lux is lumens per square meter on a surface. This tool cannot convert lumens to lux without an area.
- Unfamiliar units
- A phot is 10,000 lux and a nox is 0.001 lux.
- Meter-candle shows the same as lux
- They are the same unit, so the conversion factor is 1.