200 lux equals 200 lumens when the illuminated surface area is exactly 1 square meter. This is because lux measures illuminance (lumens per square meter), so when the area is 1 m², the lux value directly equals lumens.
Lux represents how much luminous flux hits a surface area, whereas lumens quantify total luminous flux emitted by a light source. Converting lux to lumens requires knowing the area illuminated; without area, the conversion cannot be exact.
Conversion Tool
Result in lumens:
Conversion Formula
The conversion from lux to lumens depends on the surface area illuminated. The formula is:
Lumens (lm) = Lux (lx) × Area (m²)
This works because lux measures lumens per square meter. So, when you multiply lux by the area, you get total lumens hitting that area.
For example, if you have 200 lux illuminating a 1 m² surface:
- Lux = 200 lx
- Area = 1 m²
- Lumens = 200 × 1 = 200 lm
If the area was 2 m², lumens would be 200 × 2 = 400 lm, showing the area affects total luminous flux.
Conversion Example
- Convert 150 lux to lumens on a 2 m² surface:
- Start with 150 lx
- Multiply by 2 m²: 150 × 2 = 300 lm
- Result is 300 lumens
- Convert 300 lux to lumens on a 0.5 m² surface:
- 300 lx × 0.5 m² = 150 lm
- The smaller area reduces total lumens
- Convert 100 lux to lumens on 1.5 m²:
- 100 × 1.5 = 150 lm
- Area greater than 1 increases lumens
- Convert 250 lux to lumens on 3 m²:
- 250 × 3 = 750 lm
- Large area means more lumens
Conversion Chart
| Lux (lx) | Area (m²) | Lumens (lm) |
|---|---|---|
| 175.0 | 1 | 175.0 |
| 180.0 | 1 | 180.0 |
| 185.0 | 1 | 185.0 |
| 190.0 | 1 | 190.0 |
| 195.0 | 1 | 195.0 |
| 200.0 | 1 | 200.0 |
| 205.0 | 1 | 205.0 |
| 210.0 | 1 | 210.0 |
| 215.0 | 1 | 215.0 |
| 220.0 | 1 | 220.0 |
| 225.0 | 1 | 225.0 |
The chart shows lux values from 175 to 225 for 1 square meter area. You can read the lumens in the last column. Multiply lux with area to get lumens for other surface sizes.
Related Conversion Questions
- How many lumens correspond to 200 lux on a 5 square meter floor?
- What is the lumen output if 200 lux lights a 0.75 m² desk?
- Can 200 lux be converted directly to lumens without knowing area?
- How does changing surface area affect conversion from 200 lux to lumens?
- Is 200 lux enough to equal 200 lumens for room lighting?
- What formula do I use to get lumens from 200 lux on different surfaces?
- If I measure 200 lux, how do I find total lumens emitted?
Conversion Definitions
Lux: Lux is the unit measuring illuminance, that is, how much luminous flux lands on a surface area. It tells how brightly a surface is lit, calculated as lumens per square meter. Higher lux means more light intensity on the area.
Lumens: Lumens measure luminous flux, the total quantity of visible light emitted by a source. It represents brightness output independent of area, showing how much light a bulb or lamp produces in all directions.
Conversion FAQs
Can I convert lux to lumens without the surface area?
No, you can’t accurately convert lux to lumens without knowing the area illuminated. Lux is lumens per square meter, so without the area, you don’t know total lumens. Assuming 1 m² area converts lux 1:1 to lumens, but any other area changes the value.
What happens if the surface area is larger than 1 square meter?
If the surface area is larger, total lumens increase proportionally. For example, 200 lux on 2 m² equals 400 lumens. The light spreads over bigger area, so more total light (lumens) is required to maintain same lux.
Does lux depend on the distance from light source?
Yes, lux decreases with distance from the source because light spreads out, reducing illuminance. Lumens emitted by the source remain constant, but lux on a surface changes based on how far it is from light.
Is it possible to have high lumens but low lux?
Yes, if light is spread over a large area, total lumens can be high but lux low. For example, a powerful bulb emitting 1000 lumens on a 10 m² surface yields only 100 lux, because light intensity per unit area is lower.
Why use lux instead of lumens when measuring light in rooms?
Lux better describes how much light reaches surfaces, which matters for tasks or comfort. Lumens measure total emission but don’t indicate how bright a specific spot is. Lux relates directly to perceived brightness on surfaces.