1 lux equals 1 lumen per square meter. So, when converting 1 lux to lumens, you need to multiply by the area in square meters to get lumens. Without knowing the area, 1 lux alone doesn’t directly convert to lumens.
Lux measures illuminance, which is the amount of light falling on a surface area. Lumens measure luminous flux, the total light emitted by a source. To convert lux to lumens, you multiply the lux value by the surface area illuminated in square meters.
Conversion Tool
Result in lumens:
Conversion Formula
The formula to convert lux to lumens is:
Lumens = Lux × Area (in square meters)
Lux measures how much light hits a surface per square meter, so to find out the total light output in lumens, you multiply lux by the surface area illuminated.
For example, if you have 1 lux illuminating a 2 square meter surface:
- Lux = 1
- Area = 2 m²
- Lumens = 1 × 2 = 2 lumens
This formula works because lux is lumens per square meter, so multiplying by the area cancels out the square meters unit.
Conversion Example
- Example 1: 5 lux over 3 m²
- Calculate lumens: 5 × 3 = 15 lumens
- Meaning 15 lumens of total light fall on that surface.
- Example 2: 12 lux over 0.5 m²
- Calculate lumens: 12 × 0.5 = 6 lumens
- Shows less surface area, so fewer total lumens despite higher lux.
- Example 3: 0.8 lux over 10 m²
- Calculate lumens: 0.8 × 10 = 8 lumens
- Low lux but big area results in moderate lumens.
- Example 4: 20 lux over 1.2 m²
- Calculate lumens: 20 × 1.2 = 24 lumens
- High lux and moderate area produce high lumens.
Conversion Chart
| Lux | Lumens (assuming 1 m² area) |
|---|---|
| -24.0 | -24.0 |
| -22.0 | -22.0 |
| -20.0 | -20.0 |
| -18.0 | -18.0 |
| -16.0 | -16.0 |
| -14.0 | -14.0 |
| -12.0 | -12.0 |
| -10.0 | -10.0 |
| -8.0 | -8.0 |
| -6.0 | -6.0 |
| -4.0 | -4.0 |
| -2.0 | -2.0 |
| 0.0 | 0.0 |
| 2.0 | 2.0 |
| 4.0 | 4.0 |
| 6.0 | 6.0 |
| 8.0 | 8.0 |
| 10.0 | 10.0 |
| 12.0 | 12.0 |
| 14.0 | 14.0 |
| 16.0 | 16.0 |
| 18.0 | 18.0 |
| 20.0 | 20.0 |
| 22.0 | 22.0 |
| 24.0 | 24.0 |
| 26.0 | 26.0 |
This chart shows lux values in first column, and lumens assuming the light falls on 1 square meter area. To find lumens for different areas, multiply the lumens value by the surface area in square meters.
Related Conversion Questions
- How many lumens is 1 lux on a 5 square meter surface?
- Does 1 lux always equal 1 lumen?
- What surface area do I need to convert 1 lux to 10 lumens?
- Can I convert 1 lux directly to lumens without knowing area?
- How does the size of the surface affect lumens from 1 lux?
- Is 1 lux the same as 1 lumen on a 1 m² surface?
- What formula converts 1 lux to lumens for room lighting?
Conversion Definitions
Lux: Lux is a unit measuring illuminance, the amount of visible light that hits a surface area. One lux equals one lumen per square meter. It quantifies how bright the light appears on a given surface, used in lighting design and measurements.
Lumens: Lumens measure luminous flux, the total visible light emitted by a source. It shows how much light a bulb or fixture produces in all directions. Lumens help compare brightness between different light sources.
Conversion FAQs
Why can’t I convert 1 lux directly to lumens without surface area?
Because lux measures light per square meter, it depends on the area illuminated. Lumens are total light output. Without knowing the surface size, you can’t calculate total lumens from lux alone. The area acts as a multiplier to find lumens.
What happens if the surface area is zero when converting lux to lumens?
If the surface area is zero, the lumens will always be zero because no surface exists to receive light. Multiplying lux by zero gives zero lumens, which means no light is measured as total output on any surface.
Can lux values be negative like in the chart?
Negative lux values aren’t physically meaningful because illuminance can’t be less than zero. The chart includes negative numbers just as a range example, but in real-world measurements lux is always zero or positive.
How does distance affect lux to lumens conversion?
Distance changes the area illuminated and intensity. As distance increases, lux decreases because light spreads over a bigger area. To get lumens, you multiply lux by the actual illuminated surface area at that distance, so distance indirectly affects lumens.
Are lumens the same as brightness?
Lumens quantify total light output, but brightness perception also depends on environment, eye sensitivity, and reflectivity. So lumens give an objective measurement, but perceived brightness can vary despite equal lumens.