Luminous Flux Converter
Convert between lumens, candela, lux, and foot-candles for lighting design and measurement.
Type in any field — the others update instantly.
Illuminance — light received on a surface
Total Output — convert lumens and candela (assumes uniform sphere)
Luminous flux measures the total amount of visible light emitted by a source.
Key units:
- Lumen (lm) — total light output from a source
- Candela (cd) — light intensity in a specific direction
- Lux (lx) — lumens per square meter (illuminance)
- Foot-candle (fc) — lumens per square foot (used in the US)
Relationships:
- 1 lux = 1 lumen per m²
- 1 foot-candle = 1 lumen per ft² = 10.764 lux
- 1 candela (uniform sphere) = 4π lumens ≈ 12.566 lumens
Lux to Foot-candle conversion:
- lux = foot-candles × 10.764
- foot-candles = lux × 0.0929
Typical illuminance levels:
| Environment | Lux | Foot-candles |
|---|---|---|
| Full moonlight | 0.25 | 0.023 |
| Street lighting | 10 | 0.93 |
| Home living room | 150 | 14 |
| Office workspace | 500 | 46 |
| Overcast sky | 1,000 | 93 |
| Direct sunlight | 100,000 | 9,290 |