Illuminance Converter
Convert between lux, foot-candles, phot, nox, and more illuminance units instantly.
About Illuminance Converter
Our Illuminance Converter is a comprehensive tool that allows you to convert illuminance measurements between different units seamlessly. Whether you're working on lighting design, photography, architecture, or scientific research, this tool provides accurate conversions across seven commonly used illuminance units.
The tool supports conversions between Lux (lx), Foot-candle (fc), Phot (ph), Nox, Millilux (mlx), Kilolux (klx), and Lumen per square meter (lm/m²). All conversions are calculated with high precision and displayed instantly as you type or change units.
Convert From
How to Use
Enter the Illuminance Value
Type the numerical value of the illuminance you want to convert in the "Illuminance Value" field. You can enter whole numbers, decimals, or negative values. The input accepts any valid number.
Select the Original Unit
Choose the unit of your input value from the "From Unit" dropdown. Options include Lux (lx), Foot-candle (fc), Phot (ph), Nox, Millilux (mlx), Kilolux (klx), and Lumen per square meter (lm/m²).
Select the Target Unit
Choose the unit you want to convert to from the "To Unit" dropdown. You can also use the "Swap Units" button to quickly switch between the source and target units.
View Results
Click "Convert" to see the result. The tool will display the converted value, the formula used, and all possible conversions from your original value to every supported unit.
Common Conversions
Quick links to frequently used illuminance conversions. Click any link to see the instant result.
Frequently Asked Questions
What are the different illuminance units?
Lux (lx): The SI unit of illuminance, equal to 1 lumen per square meter. Foot-candle (fc): Common in the US, where 1 fc ≈ 10.764 lx. Phot (ph): CGS unit, where 1 ph = 10,000 lx. Nox: A smaller unit, where 1 nox = 0.001 lx. Millilux (mlx): 1/1000 of a lux. Kilolux (klx): 1000 lux, used for bright conditions. Lumen/m² (lm/m²): Equivalent to lux.
How precise are the conversions?
Our converter uses high-precision mathematical calculations and displays results with up to 10 decimal places. For most practical applications, 2-4 decimal places are sufficient. You can round the result as needed for your specific use case.
What is the conversion between lux and foot-candles?
To convert from lux to foot-candles: fc = lx / 10.764. To convert from foot-candles to lux: lx = fc × 10.764. One foot-candle equals approximately 10.764 lux.
What is a typical illuminance level for different environments?
Typical illuminance levels vary widely: Starlight is about 0.002 lx, a moonlit night around 0.25 lx, a dimly lit room 50-100 lx, office lighting 300-500 lx, overcast daylight 1,000-2,000 lx, full daylight 10,000-25,000 lx, and direct sunlight can reach 100,000 lx or more.
Is this tool free to use?
Absolutely! Our Illuminance Converter is completely free to use, with no registration required. We believe in providing high-quality, accessible tools for engineers, architects, photographers, and anyone who needs to perform illuminance conversions quickly and accurately.