Lux (lx)
The lux (lx) is the SI unit of illuminance: how much light falls on a surface, measured as one lumen spread over one square meter.
Convert lux to any illuminance unit
1 lux = 0.09290304014 foot-candles
Quick facts
- Unit
- Lux
- Symbol
- lx
- Measures
- Illuminance
- System
- Units
- Definition
- One lumen per square meter.
- Also written
- lumen per square meter, lm/m²
1 lux in other units
| Foot-candles | 0.09290304014 fc |
What is a lux?
The lux (lx) is the SI unit of illuminance: how much light falls on a surface, measured as one lumen spread over one square meter. Light meters and phone apps measure lux, and lighting standards specify minimum lux levels for offices, schools, streets and workplaces.
Where the lux sits among illuminance units
The lux is number 2 of 6 on our scale of illuminance units, ordered from smallest to largest.
What lux are used for
- Workplace and office lighting standards (e.g. EN 12464-1).
- Photography and film lighting.
- Plant growing and aquarium lighting.
- Street and emergency lighting design.
Lux in real life
- Full moon on a clear night: about 0.1–0.3 lux.
- Living room at night: 50–150 lux.
- Office desk: 300–500 lux.
- Overcast day: 1,000–10,000 lux.
- Direct sunlight: up to about 100,000 lux.
History of the lux
The lux was adopted in 1948 along with the modern candela and lumen. The name is Latin for "light".
Top lux conversions
Common amounts of lux
- 0.1 lx
- 0.2 lx
- 0.3 lx
- 0.4 lx
- 0.5 lx
- 0.6 lx
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- 0.9 lx
- 1 lx
- 1.5 lx
- 2 lx
- 2.5 lx
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- 3.5 lx
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- 5 lx
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- 7.5 lx
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- 800 lx
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- 1,000 lx
- 1,200 lx
- 1,500 lx
- 2,000 lx
- 2,500 lx
- 3,000 lx
- 4,000 lx
- 5,000 lx
- 10,000 lx
Convert lux to all 5 other units
Units
Convert to lux
Frequently asked questions
What is a lux?
The lux (lx) is the SI unit of illuminance: how much light falls on a surface, measured as one lumen spread over one square meter.
How is the lux defined?
One lumen per square meter.
How many foot-candles are in a lux?
One lux equals 0.09290304014 foot-candles.