*In the planning of lighting installations, lux (illuminance) plays a significant role. On the other hand, the brightness of LED lamps and light sources is measured in lumens. *

*The relationship between the two quantities is explained here to convert lux lumens conversion appropriately. The conversion will be made more accessible with a simple calculator.*

**About lux and lumens**

Lux is a unit of measurement for the brightness of one or more light sources. This is the amount of light used to illuminate a specific region. As a result, illumination in lux is a vital planning parameter for lighting systems. This determines the luminous flux received, dependent on the beam angle and distance, not the luminous flux emitted by the light source.

Lumens are used to measure the brightness of LED bulbs. This is the total amount of light that the bulb emits in all directions. When it came to traditional light sources, the brightness was generally measured in watts. Due to the varying light output ratios of current LED bulbs.

Read More: Lumen Calculator – How do calculate the lumens of LED lights?

**Difference between lux and lumens**

The distinction between lumen and lux is that lux considers the spread of light flux (lumens) over a larger area. A flux of 1000 lumens concentrated into a one-square-meter region produces an illuminance of 1000 Lux in that area.

A 500-lumen light source, for example, lamps of 1 square meter with 500 Lux. The same light source that needs to illuminate 10 square meters only provides 50 Lux to this area.

**Lux to lumens conversion**

The correlation between the two values must be found to convert lux to lumens or lumens to lux. Other aspects play a part since it is the emitted light on the one hand and the received light on the other. These are the light source’s beam angle and the distance between it and the lit surface.

The light circle below the lamp grows in size as the beam angle and distance increase. The lumen value per square foot decreases in this instance, as does the illuminance or lux value. The opposite is alight with the same brightness but a slight beam angle or a limited distance. Because the same amount of light falls on a smaller area, the lux number rises.

Read More: Power Consumption Calculator Of Any Electrical Equipment

**How many lumens have a lux?**

1 lux equates to 1 lumen (lm) per square metre (m2) (lx). 10.764 lux equates to 1 lumen (lm) per square foot (ft2) (lx).

**Lux to the lumens calculation formula**

*#1. Lux to lumens calculation with area in square feet*

The luminous flux ΦV in lumens (lm) is equal to 0.09290304 times the illuminance Ev in lux (lx) times the surface area A in square feet (ft2):

**ΦV(lm) = 0.09290304 × Ev(lx) × A(ft2)**

For a spherical light source, the area A is equal to 4 times pi times the squared sphere radius:

*A = 4⋅π⋅r 2*

So the luminous flux ΦV in lumens (lm) is equal to 0.09290304 times the illuminance Ev in lux (lx) times 4 times pi times the squared sphere radius r in feet (ft):

*ΦV(lm) = 0.09290304 × Ev(lx) × 4⋅π⋅r(ft) 2*

So

*lumens = 0.09290304 × lux × (square feet)*

or

*lm = 0.09290304 × lx × ft2*

*#2. Lux to lumens calculation with area in square meters*

The luminous flux ΦV in lumens (lm) is equal to the illuminance Ev in lux (lx) times the surface area A in square meters (m2):

**ΦV(lm) = Ev(lx) × A(m2)**

For a spherical light source, the area A is equal to 4 times pi times the squared sphere radius:

*A = 4⋅π⋅r 2*

So the luminous flux ΦV in lumens (lm) is equal to the illuminance Ev in lux (lx) times 4 times pi times the squared sphere radius r in meters (m):

*ΦV(lm) = Ev(lx) × 4⋅π⋅r 2*

So

*lumens = lux × (square meters)*

Or

*lm = lx × m2*

Read More: Illuminance Calculator: All-to-know about Calculating Illuminance

**Calculation examples**

*#1. Convert lux to lumens*

What is the luminous flux on a surface of 4 square meters and illuminance of 500 lux?

*ΦV(lm) = 500 lux × 4 m2 = 2000 lm*

*#2. Convert lumens to lux*

What is the luminous flux on a surface of 4 square meters and illuminance of 500 lux?

*ΦV(lm) = 500 lux × 4 m2 = 2000 lm*

**What to pay attention to?**

It should be noted that when employing a single light source, the light distribution of numerous LED spotlights does not have to be uniform within the beam angle. The light intensity frequently declines, especially in the periphery. As a result, the illuminance in the light circle is not uniform.

In most circumstances, multiple LED luminaires are employed to provide the full illumination of rooms or specified areas with a low illumination intensity. The individual lights’ placements are chosen so that the light cones overlap. A professional light planner should be consulted to achieve homogenous lighting with an appropriate lux rating.

Read More: Recessed Lighting Calculator – How much light is sufficient?

**FAQs**

*#1. How many lux are 400 lumens?*

Consider purchasing a 400-lumen bulb and placing it in a room with a surface area of 10 m2. For example, a tiny toilet or storage room. Adding this to our equation, the room receives a light intensity of 40 lux on average.

*#2. Which is brighter a lux or a lumen?*

In other words, 1 lux equals 1 lumen per m2 or light intensity in a particular region. The amount of light produced in a given area is measured in Lux. One lumen per square meter equals one lux. We use lux because it is a quick and easy way to figure out how bright a beam appears to us.

*#3. How many lux are 2000 lumens?*

A lux meter can be used to measure lux. If you light a wall 2 meters away with a Suprabeam Q7xrs with 2000 lumens, the wall will have 440 lux if you use the wide 70° flood beam, but 9301 lux if you use the Hyperfocus to focus the beam into a 15° spot beam.

*#4. Is 5000 lux good for a projector?*

5000+ ANSI lumens are the ultimate brightness level to consider. This gives you an image size of 100″ or more, which is great for large conference rooms, exposition halls, auditoriums, etc. These projectors’ power allows them to perform well even in bright environments.

*#5. How many watts are 2700 lumens?*

Lumens incandescent bulb (12-18 lm/W)

LED bulb (80-100 lm/W)

- 900–1350 lm 75 W 13 W
- 1200-1800 lm 100 W 17 W
- 1800-2700 lm 150 W 25 W
- 2400-3600 lm 200 W 34 W.

*#6. Is Lux the same as nits?*

Illuminance or illumination is measured in both lux and nits. In other words, they are light intensity measurements. 10 nits equal 31.4159 lux in the sample numbers.

It’s easiest to think of a TV as emitting light directly, in much the same way as the Sun does. Nits are simply the measurement of the level of light (luminance) in a given area which the TV sends to your eyes. 1 nit is equal to one candela (one candlepower) per square meter (1cd/m2).

*#7. How much Lux do I need for an outdoor projector?*

For outdoor projectors to be appreciated during daytime hours, most experts recommend 2,500–3,000 lumens, while more is desirable on bright, sunny days. However, to project on a large screen or wall, you may need 5000 lumens or more.

*#8. How much Lux should a bike light have?*

800 Lumens = 60 Watt Bulb The number of lumens required for a bike light varies depending on the type of cycling. We will use the following as an essential guide: To be seen in daylight, daytime running lights must have a lumen output of 100 or above—50 to 200 lumens = urban commuting lights visible throughout town.

Read More:

**Conclusion**

*The relationship between lux and lumens in response to distance and angle is now clear. The online calculator can assist you in determining a lighting design reference point. *

*A lux meter placed at the proper distance from the light source can be used to verify whether the intended illuminance is being obtained with the installed luminaires. **Hope our Lux Lumens Conversion tool can help you convert from Lux to Lumen easily. *