Foot-candle to Lux Converter
Converts foot-candle to lux (fc to lx) and back. The conversion factor is shown below every result.
How to Convert Foot-candle to Lux
What Is a Foot-candle?
The foot-candle (fc) is a US customary unit of illuminance equal to one lumen per square foot.
What Is a Lux?
The SI illuminance unit, lux (lx), equals one lumen per square meter.
Common Foot-candle to Lux Reference Points
Real-world reference values for quick sanity checks.
| Item | Foot-candle (fc) | Lux (approx.) |
|---|---|---|
| Recommended reading light (approx.) | 30 fc | 322.92 lux |
| Typical office lighting (approx.) | 46.45 fc | 500.0 lux |
| Reference values are illustrative approximations for common items, not measured specifications. | ||
Foot-candle to Lux Conversion Table
| Foot-candle (fc) | Lux (lx) |
|---|---|
| 1 fc | 10.76391 lx |
| 10 fc | 107.639104 lx |
| 30 fc | 322.917313 lx |
| 50 fc | 538.195521 lx |
| 100 fc | 1076.391042 lx |
| 500 fc | 5381.955208 lx |
| Source: NIST SP 811 (1 fc = 10.763910416709722 lux exactly, from 1 ft = 0.3048 m) | |
Frequently Asked Questions
How do I convert foot-candles to lux?
Multiply the foot-candle value by 10.7639104167. For example, 50 fc × 10.7639104167 = 538.196 lux.
Why do US lighting specs still use foot-candles?
Foot-candles remain common in US building codes, lighting design standards, and photography light-meter readings, alongside the more internationally standard lux.
Is this conversion exact?
Yes. It comes directly from the exact foot-to-meter definition (0.3048 m), squared for area, with no independent rounding.
Related Illuminance Converters
A good measuring tool marked in both fc and lx removes the guesswork at the point of use.