Lux ↔ Foot-Candles
Live bidirectional conversion • Professional grade precision
About This Tool
The Lux to Foot-Candles Converter is a precise, client-side web utility designed for lighting designers, architects, photographers, filmmakers, and engineers who need fast and accurate illuminance conversions between metric and imperial units.
Illuminance, the measure of light falling on a surface, is expressed in lux (lumens per square meter) in the SI system and foot-candles (lumens per square foot) in the imperial system. The exact mathematical relationship is 1 foot-candle = 10.763910416709722 lux, derived from the international foot definition of exactly 0.3048 meters. This tool applies that precise factor in real time, eliminating approximation errors common in manual calculations or simplified charts.
Built as a fully static, stateless application, all conversions happen instantly in your browser with no data sent to any server. This ensures complete privacy and allows offline use after the initial page load. The interface supports two precision levels: a clean default mode rounded to two decimal places for everyday practical work, and a high-precision mode that displays up to twenty decimal places for scientific, compliance, or detailed engineering tasks. Toggle between modes without losing your current values.
Additional features include one-click copy buttons next to each field, making it effortless to transfer results into reports, spreadsheets, design software, or emails. A reset button clears both fields instantly. The converter is mobile-responsive and works seamlessly across devices, supporting keyboard navigation for accessibility.
This utility bridges the gap between metric and imperial workflows, which is especially valuable for international projects, equipment calibration, and cross-disciplinary collaboration. Whether you are specifying office lighting levels, balancing studio exposures, or verifying architectural compliance, the tool delivers mathematically exact results with minimal friction. It complements our blog series on illuminance standards, precision considerations, and real-world applications in photography, filmmaking, and workplace design.
Our goal is to provide reference-grade utilities that prioritize accuracy, simplicity, and user privacy. By keeping everything client-side and free of tracking, we ensure you can focus entirely on your lighting calculations with confidence and peace of mind.
How to Use the Converter
Live Bidirectional Input
Simply type any numeric value into the Lux field or the Foot-Candles field. The opposite field updates instantly in real time as you type. No buttons or page refreshes are required. The tool automatically clears the opposite field if you delete your input.
Precision Mode
By default, results are shown rounded to two decimal places for clean, practical readability. Click the Precision Mode button to switch to twenty decimal places for maximum mathematical accuracy. The current values automatically reformat when you toggle modes.
Instant Copy & Reset
Use the Copy button next to each field to send the displayed value to your clipboard with one click. A brief “Copied” confirmation appears. The Reset button clears both fields instantly, allowing you to start fresh calculations quickly.
The conversion uses the exact factor 1 fc = 10.763910416709722 lx. All operations run locally in your browser, ensuring speed, privacy, and the ability to work offline once the page has loaded.