Lux To Footcandle
Convert illuminance between lux and footcandles instantly using fc = lx / 10.76391. Free online light intensity converter for photography, lighting design, and architecture.
About This Calculator
This lux to footcandle converter lets you instantly convert between the two most widely used units for measuring illuminance — the amount of light received per unit area. Whether you are a lighting designer, architect, photographer, engineer, or student, this tool helps you switch between the international SI standard (lux) and the US customary unit (footcandle) with a single click.
Lux (lx) and footcandle (fc) both measure illuminance but on different area bases. One lux equals one lumen per square meter, while one footcandle equals one lumen per square foot. Since one square foot equals 10.76391 square feet, the conversion factor between the two units is 10.76391. To convert lux to footcandles, divide by 10.76391. To convert footcandles to lux, multiply by 10.76391.
Regional Notes: The United States uses footcandles as the standard unit for lighting codes, building regulations, and workplace illumination standards (ANSI/IES). Most other countries, including India, the UK, Canada, Australia, and all of Europe, use lux as the official SI unit. When specifying lighting requirements internationally, always confirm which unit the local standards require.
Frequently Asked Questions
How do you convert lux to footcandles?
To convert lux to footcandles, divide the lux value by 10.76391. For example, 100 lux equals approximately 9.29 footcandles. The formula is: fc = lx / 10.76391.
How do you convert footcandles to lux?
To convert footcandles to lux, multiply the footcandle value by 10.76391. For example, 10 footcandles equals approximately 107.64 lux. The formula is: lx = fc × 10.76391.
What is the difference between lux and footcandle?
Lux and footcandles both measure illuminance — the amount of light received per unit area. Lux uses square meters (1 lx = 1 lm/m²) and is the international SI standard. Footcandles use square feet (1 fc = 1 lm/ft²) and are primarily used in the United States. One footcandle equals 10.76391 lux.
When should I use footcandles instead of lux?
Footcandles are the standard unit in the United States for lighting design, architecture, and building codes. Lux is used everywhere else in the world. If you are working with American building standards, electrical codes, or US-based lighting specifications, footcandles are the appropriate unit.
What are typical lux and footcandle values for common environments?
A bright sunny day is about 10,000-25,000 lux (930-2,325 fc). An office workspace needs 300-500 lux (28-46 fc). A living room is typically 100-300 lux (9-28 fc). Street lighting provides about 10-50 lux (1-5 fc). Starlight is only about 0.0001 lux.
Is this lux to footcandle converter free?
Yes, this converter is completely free to use with no registration or sign-up required. You can bookmark it for quick conversions anytime.