# Lux to lumens calculator Convert illuminance from lux (lx) to luminous flux in lumens (lm) effortlessly. Perfect for lighting design, photometry, and light measurement calculations. Obtain accurate lumen measurements by converting lux using this convenient online tool.

 Enter Illuminance in lux: lx Select area unit type: Area in square feet Area in square meters Enter spherical radius: Or enter surface area: Luminous flux result in lumens: lm

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## What is Lux to lumens

Lux (lx) and lumens (lm) are units of measurement used in lighting. Lux measures illuminance, which is the amount of light that falls on a surface. Lumens, on the other hand, measure luminous flux, which is the total amount of visible light emitted by a light source.

The relationship between lux and lumens depends on the area being illuminated and the distance from the light source. To convert lux to lumens, you need to know the area of the surface being illuminated and the distance from the light source.

The formula for converting lux to lumens is:

Lumens (lm) = Lux (lx) x Area (in square meters)

To use this formula, multiply the lux value by the area of the surface being illuminated in square meters.

It's important to note that this conversion assumes that the light is evenly distributed over the surface and that the distance from the light source is accounted for. Additionally, the conversion may vary depending on the efficiency of the light source and any losses in the optical system.

When converting between lux and lumens, it's recommended to consult the specifications provided by the manufacturer or refer to photometric data specific to the light source being used for a more accurate conversion.

## Lux to lumens calculation formula

### 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

### 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

### Lux to lumens Example#1

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

## Lux to lumens calculator Example

To convert Lux (lx) to Lumens (lm), you need to consider the area over which the illuminance is measured. The equation for this conversion is:

Lumens (lm) = Lux (lx) × Area (in square meters)

Here's an example to demonstrate the conversion using a calculator:

Let's assume you have a light source with different illuminance values in Lux (lx) and you want to calculate the equivalent luminous flux in Lumens (lm) for a specific area. For this example, we'll use an area of 4 square meters:

Illuminance (lx) Luminous Flux (lm)
1000 4000
500 2000
200 800
100 400

To convert the illuminance from Lux to Lumens, multiply the value in Lux by the area in square meters.

For example, if the illuminance is 1000 lx and the area is 4 square meters, the luminous flux would be 1000 lx × 4 square meters = 4000 lm.

Similarly, for an illuminance of 500 lx and the same area of 4 square meters, the luminous flux would be 500 lx × 4 square meters = 2000 lm.

You can perform the same calculation for other illuminance values in the table, multiplying each value by the area in square meters.

Please note that these calculations assume the light is evenly distributed over the specified area. The actual conversion may vary depending on the specific characteristics of the light source and the distribution of light.