Lux to Foot-candle Converter
Converts lux to foot-candle (lx to fc) and back. The conversion factor is shown below every result.
How to Convert Lux to Foot-candle
What Is a Lux?
Lux (lx) is the SI unit of illuminance, equal to one lumen per square meter.
What Is a Foot-candle?
The foot-candle (fc) is a US customary unit of illuminance equal to one lumen per square foot (10.763910416709722 lux).
Common Lux to Foot-candle Reference Points
Real-world reference values for quick sanity checks.
| Item | Lux (lx) | Foot-candle (approx.) |
|---|---|---|
| Typical office lighting (approx.) | 500 lx | 46.45 fc |
| Direct sunlight (approx.) | 100000 lx | 9,290.3 fc |
| Reference values are illustrative approximations for common items, not measured specifications. | ||
Lux to Foot-candle Conversion Table
| Lux (lx) | Foot-candle (fc) |
|---|---|
| 10 lx | 0.92903 fc |
| 50 lx | 4.645152 fc |
| 100 lx | 9.290304 fc |
| 500 lx | 46.45152 fc |
| 1000 lx | 92.90304 fc |
| 10000 lx | 929.0304 fc |
| 100000 lx | 9290.304 fc |
| Source: NIST SP 811 (1 fc = 10.763910416709722 lux exactly, from 1 ft = 0.3048 m) | |
Frequently Asked Questions
How do I convert lux to foot-candles?
Divide the lux value by 10.7639104167 (or multiply by 0.09290304). For example, 500 lux × 0.09290304 = 46.452 fc.
Why is the factor exactly 0.09290304?
It's the exact square of the foot-to-meter definition (0.3048²), since illuminance is measured per unit area and area scales as the square of length.
What's a typical recommended lux level?
General office lighting is commonly recommended around 300 to 500 lux, while direct sunlight can exceed 100,000 lux; the right level depends heavily on the specific task and application.
Related Illuminance Converters
A good measuring tool marked in both lx and fc removes the guesswork at the point of use.