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1 lux equals 1 lumen per square meter, so converting 1 lux to lumens depends on the area illuminated. For example, if the illuminated area is 1 square meter, then 1 lux equals 1 lumen.
Lux measures illuminance, which is lumens spread over an area. Lumens measure total light output. Therefore, to convert lux to lumens, you multiply the lux value by the area in square meters. Without an area, the conversion is incomplete.
Table of Contents
Conversion Tool
Result in lumens:
Conversion Formula
The conversion between lux and lumens depends on the size of the illuminated surface. Lux is lumens per square meter, so the formula to convert lux to lumens is:
Lumens = Lux × Area (in square meters)
This formula works because lux measures how much light falls onto a surface, while lumens measure the total light output. If you know the lux level and the area, multiply them to find the total lumens.
Example:
- Given: 1 lux and area = 2 m²
- Calculate: Lumens = 1 × 2 = 2 lumens
- So, 1 lux over 2 square meters equals 2 lumens total.
Conversion Example
- Convert 5 lux on 3 m²:
- Multiply 5 (lux) by 3 (m²)
- Result: 15 lumens
- Explanation: The light spreads over 3 m², so total lumens is higher.
- Convert 10 lux on 0.5 m²:
- 10 × 0.5 = 5 lumens
- Since area is half, total lumens is less than lux value.
- Convert 0.2 lux on 4 m²:
- 0.2 × 4 = 0.8 lumens
- Small lux value, but bigger area increases lumens.
Conversion Chart
Below is a chart showing lux values from -24.0 to 26.0 converted to lumens assuming 1 square meter area. The lumens equal lux times area, so each lux value corresponds directly to lumens here.
| Lux | Lumens (Area = 1 m²) |
|---|---|
| -24.0 | -24.0 |
| -20.0 | -20.0 |
| -16.0 | -16.0 |
| -12.0 | -12.0 |
| -8.0 | -8.0 |
| -4.0 | -4.0 |
| 0.0 | 0.0 |
| 4.0 | 4.0 |
| 8.0 | 8.0 |
| 12.0 | 12.0 |
| 16.0 | 16.0 |
| 20.0 | 20.0 |
| 24.0 | 24.0 |
| 26.0 | 26.0 |
To read the chart, find the lux value of interest in first column and then see corresponding lumens for area of 1 m². For other areas, multiply lumens by the surface size.
Related Conversion Questions
- How many lumens are in 1 lux over 5 square meters?
- What is the formula to convert 1 lux to lumens when area is known?
- Can 1 lux equal 1 lumen without considering area?
- How does increasing area affect lumens if lux is 1?
- Is 1 lux always less than or greater than 1 lumen?
- Why does 1 lux not equal 1 lumen in some cases?
- How to calculate lumens from 1 lux and 3 square feet?
Conversion Definitions
Lux: Lux is a unit measuring illuminance, describing how much luminous flux hits a square meter of surface. It quantifies the intensity of light perceived by the human eye on a given area. Lux depends on both light source and distance to surface.
Lumens: Lumens measure the total amount of visible light emitted by a source, regardless of direction. It indicates the brightness of a light source itself, without considering area or distance of illumination.
Conversion FAQs
Can lux values be negative?
In practice lux cannot be negative since it represents light intensity, which cannot be less than zero. Negative values might appear in calculations or instruments due measurement errors or calibration issues, but physically they do not exist.
Does converting lux to lumens require knowing the area?
Yes, because lux is lumens per square meter, the area illuminated must be known to convert lux back to lumens. Without area information, conversion only gives partial information.
Are lumens and lux interchangeable units?
No, lumens measure total light output, while lux measures light intensity on a surface area. Interchangeable only when area is known and factored in.
What happens if area is zero in conversion?
If area equals zero, conversion from lux to lumens results zero lumens since no surface to receive light. This is a theoretical edge case, practically area cannot be zero.
How to convert lux to lumens for irregular shapes?
For irregular shapes, calculate the total surface area first, then multiply lux by that area. Estimating area accurately is necessary for correct lumens conversion.
