Illuminance Converter
Convert illuminance measurements between lux and foot-candles for lighting design, photography, and architectural applications
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Complete Guide: Illuminance Converter
Everything you need to know about using this tool effectively
The Illuminance Converter transforms light intensity measurements between lux, foot-candles, and phot. Lux is the SI unit used internationally. Foot-candles are the imperial equivalent used in the US. Phot is a less common unit used in some scientific contexts. The tool converts between all three using exact factors. All processing happens in the browser.
This tool applies standard illuminance conversion factors: 1 foot-candle = 10.7639 lux, 1 phot = 10,000 lux. You enter a value in one unit and see the equivalent in the other two.
Designing workplace lighting
Convert a lux specification to foot-candles to match US lighting standards.
Setting up photography lighting
Convert foot-candle meter readings to lux for documentation or equipment comparison.
Comparing international lighting standards
Convert European lux requirements to foot-candles for US compliance.
Evaluating natural light levels
Convert a foot-candle reading from a light meter to lux for a report.
Enter a value
Type the illuminance and select the source unit.
View the conversions
The tool shows the equivalent in the other two units.
Copy the result
Copy the value you need.
1 foot-candle = 10.7639 lux.
Office lighting typically requires 300-500 lux.
Direct sunlight is about 100,000 lux.
Lux is the SI standard. Foot-candles are used primarily in the US.
What is the difference between lux and foot-candles?
Both measure illuminance (light intensity). Lux is the SI unit used internationally. Foot-candles are the imperial equivalent used in the US. 1 foot-candle equals 10.7639 lux.
Is my data sent to a server?
No. All conversion happens in your browser. Nothing is transmitted.
What is a phot?
Phot is a CGS unit of illuminance equal to 10,000 lux. It is rarely used today but appears in some older scientific literature.
When would I need this converter?
Lighting designers, photographers, and safety engineers commonly need to convert between lux and foot-candles when working with international standards or equipment from different regions.
Can I convert decimal values?
Yes. The tool accepts any positive number including decimals.