What this converter does
This converter turns lux into foot-candles and back. Both measure illuminance — how much light lands on a surface — with lux the metric unit and the foot-candle the US one. One foot-candle equals 10.764 lux. Type a value and read the result instantly.
A 500-lux office equals about 46 foot-candles. For the reverse, use the foot-candle to lux converter.
The units it covers
Illuminance is luminous flux per unit area. Every unit converts through the lux with a fixed ratio.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Lux | lx | 1 | SI unit (lumen per m²) |
| Foot-candle | fc | 10.764 | US lighting design (lumen per ft²) |
| Lumen per m² | lm/m² | 1 | Same as lux |
| Phot | ph | 10000 | CGS unit (lumen per cm²) |
The formula
Each unit has a fixed value in lux, so converting between any two goes through lux once:
result = value × factor_from ÷ factor_toWhere:
- value = the illuminance you typed, in the “from” unit
- factor_from = the “from” unit’s value in lux
- factor_to = the “to” unit’s value in lux
Worked example
Convert an office level of 500 lux to foot-candles.
1 fc = 10.7639 lx500 ÷ 10.7639 = 46.45 fcSo a 500-lux office is about 46 foot-candles.
The units in this example
The SI unit of illuminance — one lumen per square metre. Used in metric lighting standards worldwide.
- 1 lx = 0.0929 fc
- Office ≈ 500 lx
- Corridor ≈ 100 lx
- Overcast day ≈ 1,000 lx
The US unit of illuminance — one lumen per square foot. Common in North American lighting design.
- 1 fc = 10.764 lx
- Office ≈ 46 fc
- Parking lot ≈ 2 fc
- Detailed task ≈ 75 fc