Illuminance in lux (lx) to footcandles (fc) conversion calculator and how to convert.

Enter the illuminance in lux (lx) and press the *Calculate* button to get the illuminance in footcandles (fc):

#### Lux to footcandles conversion formula

The illuminance *E*_{v} in footcandles (fc) is equal to the illuminance *E*_{v} in lux (lx) times 0.09290304:

*E*_{v(fc)} =
*E*_{v(lx)}* *× 0.09290304 =
*E*_{v(lx)}* */ 10.76391

The lux to lumens calculator below will help you choose the illumination solution that best meets the specific requirements of your application. Banner Engineering offers a number of high-quality, energy-efficient LED lighting products that can be used to solve a diverse range of industrial applications.

**Lux**: The amount of light that is cast on a surface is called *illuminance*, which is measured in lux. This can be thought of as light intensity within a specific area.

**Lumens**: The total output of visible light from a light source is measured in lumens. Typically, the more lumens a light fixture provides, the brighter it is.

One lux is equal to one lumen per square meter (lux = lumens/m^{2}). Essentially, as light travels from the emitter, it will disperse throughout an area. The further the light has to travel the more it will be dispersed. Therefore, the amount of lux in an area or on a surface can vary depending upon the distance the light travels and the angle at which it is dispersed.

Where the lumens provided by a given emitter are the same, light that travels less distance and/or is more narrowly focused will appear brighter because lux are concentrated in a smaller area than light that has traveled a greater distance and has been dispersed over a wider area.

Illuminance in lux (lx) to luminous flux in lumens (lm) calculator and how to calculate.

Enter the illuminance in lux (lx), select area unit type, enter radius in meters for spherical light source or surface area

#### Lux to lumens calculation formula

Calculation with area in square feet

The luminous flux *Φ*_{V} in lumens (lm) is equal to 0.09290304 times the illuminance *E*_{v} in
lux (lx) times the surface area *A* in square feet (ft^{2}):

*Φ*_{V(lm)} = 0.09290304* *×*
E*_{v(lx)}* *×* A*_{(ft}2_{)}

The luminous flux *Φ*_{V} in lumens (lm) is equal to 0.09290304 times the illuminance *E*_{v} in
lux (lx) times 4 times pi times the squared sphere radius r in feet (ft):

*Φ*_{V(lm)} = 0.09290304* *×*
E*_{v(lx)}* *×* *4⋅π⋅*r*_{(ft)}* *^{2}

#### Calculation with area in square meters

The luminous flux *Φ*_{V}
in lumens (lm) is equal to the illuminance *E*_{v} in lux (lx) times the surface area *A* in square meters (m^{2}):

*Φ*_{V(lm)} = *E*_{v(lx)}* *×* A*_{(m}2_{)}

The luminous flux * Φ*_{V} in lumens (lm) is equal to the illuminance *E*_{v} in
lux (lx) times 4 times pi times the squared sphere radius r in meters (m):

*Φ*_{V(lm)} = *E*_{v(lx)}* *×*
*4⋅π⋅*r *^{2}_{(m}2_{)}

It is a conversion calculator used to convert the illuminance in lux (lx) to the electric power in watts (W). It has four text fields and two controls that perform different functions of the calculator. The ‘Calculate’ button is used to execute the conversions from lux to watts while the ‘Reset’ button is used to erase all data of the previous calculations from the text fields.

The initial step is to enter the value of illuminance in lux. Select the light source in the options provided by the calculator. You can also fill in the luminous efficacy in lumens per watt in the next text field. Afterwards, enter the surface area or the spherical radius and then click the ‘Calculate’ button. The power result in watts will be displayed in the bottom platform below the two controls.

#### For example;

Determine the power consumption if the illuminance in lux is 450 (lx) with a luminous efficacy of 17 lumens per watt and a surface area of 100 square feet.

When using the calculator, you will first enter 450 in the first text field, and then 17 as the luminous efficacy in lumens per watt. Proceed to the next text field and enter 100 as the surface area and then click the ‘Calculate’ button.

The spherical radius will be calculated automatically as; 2.8209479177 ft and the power result in watts as; 245.91981176 watts (W).

#### Lux to watts calculation formula

Lux to watts calculation with area in square feet

The power P in watts (W) is equal to the 0.09290304 times the illuminance *E*_{v} in lux (lx) times the surface area *A* in square feet (ft^{2}), divided by the luminous
efficacy * η* in lumens per watt (lm/W):

*P*_{(W)} = 0.09290304* *×* E*_{v(lx)}* *×* A*_{(ft}2_{)} /* η*_{(lm/W)}

#### Lux to watts calculation with area in square meters

The power P in watts (W) is equal to the illuminance *E*_{v} in lux (lx) times the surface area *A* in square meters (m^{2}), divided by the luminous
efficacy * η* in lumens per watt (lm/W):

*P*_{(W)} = *E*_{v(lx)}* *×* A*_{(m}2_{)} /* η*_{(lm/W)}

It is a conversion calculator used to convert the luminous intensity in Millicandela to luminous flux in lumens. It is comprised of two text fields and two controls each performing an independent function of the calculator. Since Millicandela and lumens are of different quantities, the apex angle in degrees is required for the conversion to be successful. The initial step is to enter the value of luminous intensity in Millicandela. Proceed to the next text field and enter the apex angle in degrees then click the ‘Calculate’ button. If you want to perform new conversions you will use the ‘Reset’ button to clear the previous calculations from the text fields. The luminous flux result in lumens will be displayed below the two controls in the bottom platform of the calculator.

#### For example;

Determine the luminous flux in lumens if the luminous intensity in Millicandela is 156 (mcd) with an apx angle of 64°.

When using the calculator, you will first enter 156 as the value in Millicandela and 64 as the apex angle in degrees respectively. Afterwards, click the ‘Calculate’ button to initiate the conversion.

The luminous flux result in lumens will be; 0.14893974726 lm.

For uniform, isotropic light source, the luminous flux Φ_{v }
in lumens (lm) is equal to the luminous intensity *I*_{v} in millicandela (mcd),

times the solid angle *Ω* in steradians (sr) divided by 1000:

*Φ*_{v(lm)} = *I*_{v(mcd)} × *Ω*_{(sr)} / 1000

The solid angle *Ω* in steradians (sr) is equal to 2 times pi times 1 minus cosine of half the apex angle *θ* in degrees (°):

*Ω*_{(sr)} = 2π(1 - cos(*θ*/2))

The luminous flux Φ_{v }
in lumens (lm) is equal to the luminous intensity *I*_{v} in millicandela (mcd),

times 2 times pi times 1 minus cosine of half the apex angle *θ* in degrees (°) divided by 1000:

*Φ*_{v(lm)} = *I*_{v(mcd)} × ( 2π(1 - cos(*θ*/2)) ) / 1000

So

lumens = millicandela × ( 2π(1 - cos(degrees/2)) ) / 1000

Or

lm = mcd × ( 2π(1 - cos(°/2)) ) / 1000

**What the watt?**When buying an incandescent bulb, the watts rating gives consumers a good indication of how bright a bulb is. The more watts, the brighter the bulb.

That rule doesn't apply to LED bulbs, though. An LED that uses 60 watts is in no way comparable to an incandescent bulb that uses 60 watts. In fact, a 60-watt LED just may blind you. LEDs are designed to use less energy and naturally have a lower watt rating. This means it's useless to use watts to determine brightness.

To fix the problem, bulb companies have started using lumens to rate bulbs. This gives you a more accurate indication of how much light to expect from an LED.

**Why lumens?**Measuring in lumens isn't a new concept designed just for LEDs. It's a rating that's been used for decades as a measurement of how much light a bulb (or anything else) emits.

watts (W) to luminous flux in lumens (lm) calculator and how to calculate.

Energy saving lamps have high luminous efficacy (more lumens per watt).

The luminous flux *Φ*_{V} in lumens (lm) is equal to the power P in watts (W), times the luminous efficacy * η* in lumens per watt (lm/W):

*Φ*_{V(lm)} = *P*_{(W)} × *η*_{(lm/W)}

It is used to convert the electric power in watt (W) to illuminance in lux (lx). It has four text fields and options of executing the conversion. The watts to lux calculator also has two controls, ‘Calculate’ and ‘Reset’ buttons which operate independently performing different functions of the calculator. The first step is to enter the value of power in watts.

Select the light source in the options provided by the calculator. If you do not find the particular appliance, you will manually enter the value of luminous efficacy in lumens per watt. The next step is to enter the surface are or the spherical radius and then click the ‘Calculate’ button to initiate the process of conversion. Your results are displayed within a single click in the bottom platform of the calculator below the two controls.

#### For example;

Determine the illuminance in lux of a LED lamp having 240 watts and a surface area of 1000 square feet.

#### Watts to lux calculation formula

Watts to lux calculation with area in square feet

The illuminance *E*_{v} in lux (lx) is equal to 10.76391 times the power P in watts (W), times the luminous efficacy * η*
in lumens per watt (lm/W) divided by the surface area *A* in square feet (ft^{2}):

*E*_{v(lx)} = 10.76391 ×* P*_{(W)}* *×* η*_{(lm/W)}* */* A*_{(ft}2_{)}

#### Watts to lux calculation with area in square meters

The illuminance *E*_{v} in lux (lx) is equal to the power P in watts (W), times the luminous efficacy * η* in
lumens per watt (lm/W) divided by the surface area *A* in square meters (m^{2}):

*E*_{v(lx)} = * P*_{(W)}* *×* η*_{(lm/W)}* */* A*_{(m}2_{)}