Lux to Foot Candles Converter

Convert between lux and foot candles - two common units for measuring illuminance

Illuminance Conversion Calculator

lx

International standard unit (lumens per square meter)

fc

US standard unit (lumens per square foot)

Conversion Results

Enter a value in either field to see the conversion

Quick Reference Conversions

1 lux = 0.0929 foot candles

10 lux = 0.929 foot candles

100 lux = 9.29 foot candles

1000 lux = 92.9 foot candles

1 foot candle = 10.764 lux

10 foot candles = 107.64 lux

50 foot candles = 538.2 lux

100 foot candles = 1076.4 lux

Example Calculations

Office Lighting Example

Office illuminance requirement: 500 lux

Conversion to foot candles:

fc = 500 lx ÷ 10.76391 = 46.45 foot candles

Result: Office needs approximately 46.5 foot candles

Reading Light Example

Reading requirement: 30 foot candles

Conversion to lux:

lx = 30 fc × 10.76391 = 322.92 lux

Result: Need approximately 323 lux for comfortable reading

Common Illuminance Levels

Starlight0.0001 lux
Moonlight0.25 lux
Street lighting10-20 lux
Living room50 lux
Office work300-500 lux
Supermarket750 lux
Direct sunlight100,000 lux

Unit Comparison

Lux (lx)

  • • International standard unit
  • • Lumens per square meter
  • • Used worldwide
  • • Metric system unit

Foot Candles (fc)

  • • US standard unit
  • • Lumens per square foot
  • • Common in North America
  • • Imperial system unit

Understanding Illuminance Units

What is Illuminance?

Illuminance is the amount of light that falls on a surface per unit area. It measures how bright or dark a space feels and depends on both the light source's luminous flux (lumens) and the distance from the source.

Key Differences

  • Lux: Measures illuminance per square meter (SI unit)
  • Foot candles: Measures illuminance per square foot (Imperial unit)
  • 1 square meter = 10.76391 square feet

Conversion Formulas

fc = lx ÷ 10.76391

lx = fc × 10.76391

Practical Applications

  • Architectural lighting design
  • Workplace safety standards
  • Photography and videography
  • Energy efficiency calculations

Relationship with Lumens

Both lux and foot candles are derived from lumens, which measure the total amount of light emitted by a source:

  • Lumens (lm): Total light output from a source
  • Lux (lx): Lumens per square meter (lm/m²)
  • Foot candles (fc): Lumens per square foot (lm/ft²)