Lux to Foot Candles Converter

Foot-candles are the imperial unit of illuminance, still common in US lighting design.

How the Math Works

The conversion between lux and foot-candles relies on a fixed mathematical relationship: 1 foot-candle (fc) equals 10.764 lux (lx). To convert from lux to foot-candles, divide the lux value by 10.764; conversely, multiply a foot-candle value by 10.764 to obtain lux. This linear scaling ensures precise interchangeability between the two units, which measure illuminance—the amount of luminous flux per unit area. The formula simplifies calculations for lighting comparisons, energy efficiency assessments, and scientific applications requiring standardized units.

Practical Applications

This converter is essential for professionals in lighting design, photography, architecture, and industrial settings. For instance, when planning a workspace, engineers might use it to ensure compliance with recommended lighting levels (e.g., 500 lx for computer work, which equals ~46.45 fc). In photography, filmmakers adjust lighting setups by converting between lux (common in technical specs) and foot-candles (used in some equipment manuals). Retailers and event planners also rely on this tool to balance ambient and task lighting across venues, ensuring optimal visibility while conserving energy.

Day-to-Day Use

In everyday life, understanding this conversion helps optimize home and workspace lighting. For example, when setting up a reading nook, you might compare a lamp’s brightness in lux (e.g., 700 lx) to foot-candles (~65 fc) to ensure it meets recommended levels for comfort. It’s also useful when shopping for light bulbs: a 800-lumen bulb produces approximately 74.31 fc, helping you choose the right brightness for tasks like cooking or crafting. Additionally, it aids in interpreting energy-saving initiatives, such as switching from incandescent to LED lights, by quantifying actual light output in familiar units.

Worked example

500 lux → about 46.5 foot-candles.

FAQ