1 lux equals 1 lumen per square meter. Therefore, converting 1 lux to lumen depends on the area over which the light is spread.
Lux is a measurement of illuminance, or how much light falls on a surface, while lumen measures the total amount of visible light emitted. Converting lux to lumen requires multiplying the lux value by the area in square meters. For 1 lux, the lumen value equals the area in square meters.
Conversion Tool
Result in lumen:
Conversion Formula
The formula to convert lux to lumen is:
lumen = lux × area (in square meters)
Lux measures illuminance: the amount of light hitting a surface per unit area. Lumen measures the total light emitted by a source. So, when you multiply lux by the surface area, you get the total lumen output over that area.
Example calculation:
- If illuminance is 1 lux on a 2 m² surface, lumen = 1 lux × 2 m² = 2 lumens.
- This means the light source emits 2 lumens over that area.
Conversion Example
- Convert 5 lux over 3 m²:
- Multiply 5 lux by 3 m²
- 5 × 3 = 15 lumens
- So, 5 lux equals 15 lumens over 3 square meters.
- Convert 10 lux over 0.5 m²:
- 10 × 0.5 = 5 lumens
- Meaning 10 lux corresponds to 5 lumens on half a square meter.
- Convert 0.2 lux over 10 m²:
- 0.2 × 10 = 2 lumens
- Result shows that 0.2 lux equals 2 lumens on a 10 m² surface.
Conversion Chart
The following table shows lux values from -24.0 to 26.0 and their equivalent lumen values assuming 1 m² surface area. Negative lux values are not physically meaningful but are included for completeness.
| Lux | Lumen (1 m² area) |
|---|---|
| -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 use the chart, find your lux value in the left column, then read across to see the corresponding lumen value if the illuminated surface is 1 m². For other areas, multiply lumen by area.
Related Conversion Questions
- How do I convert 1 lux to lumens for a 5 square meter room?
- What is the lumen output if I have 1 lux shining on 0.2 square meters?
- Can I directly convert 1 lux to lumens without knowing the area?
- How does surface area affect converting 1 lux to lumen?
- If a light meter reads 1 lux, how many lumens does that represent on 3 square meters?
- Is 1 lux equal to 1 lumen always?
- How to calculate total lumens from 1 lux in a room with 10 m² floor space?
Conversion Definitions
Lux: Lux is a unit measuring illuminance, indicating how much luminous flux is spread over a specific area. One lux equals one lumen per square meter, quantifying the intensity of light that hits or passes through a surface, important for lighting design and measurement.
Lumen: Lumen measures the total amount of visible light emitted by a source. It quantifies brightness as perceived by the human eye, regardless of area. One lumen represents the light produced by a single candle spread uniformly over a sphere.
Conversion FAQs
Why does the area affect converting lux to lumens?
Lux measures light per unit area, so the total light output (lumens) depends on how big the area is. If the same lux value covers a larger surface, total lumens increase accordingly because more light is spread over that space.
Can I convert lux to lumens without knowing the area?
No, because lux is illuminance, meaning lumens per square meter. Without the area, you can’t find total lumens since it’s the product of lux and area. Assuming an area is necessary to get lumens from lux.
Are lux and lumens interchangeable units?
No, lux and lumens measure different things. Lux quantifies light intensity on a surface area, while lumens measure total light emitted by a source. Confusing them leads to wrong calculations in lighting design.
What happens if I assume area incorrectly when converting?
Assuming wrong area leads to incorrect lumen results. For example, using a bigger area than actual overestimates lumens, while smaller area underestimates total light output. Accurate area measurement is critical for precise conversion.
Why are negative lux values shown in some charts?
Negative lux values are not physically possible as light can’t be negative. They may appear in tables or calculations due to data errors or for mathematical completeness but should be disregarded in practical use.