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Lumens to lux calculator

Lumens to lux calculator

We are offering  Luminous flux in lumens (lm) to illuminance in lux (lx) calculator to make your calculations easy, check now! All you need to do is to enter the luminous flux in lumens and select the area unit type, enter radius in meters for the spherical light source or the total surface area which is measured in square meters for any light source and hit the = button to obtain the illuminance in lux.

Enter luminous flux in lumens: lm
Select area unit type:  
Enter spherical radius:
Or enter surface area:
   
Illuminance result in lux: lx

Formula for Lumens to lux calculation

Calculation with the area in square feet

The illuminance Ev which is measured in lux (lx) is apparently equal to 10.76391 times the value of luminous flux ΦV in lumens (lm) and finally divided by the surface area A measured in square feet (ft2).

Ev(lx) = 10.76391 × ΦV(lm) / A(ft2)

The illuminance Ev measured in lux (lx) is apparently equal to 10.76391 times the value of luminous flux ΦV in lumens (lm) which is divided by 4 times the value of pi, further multiplied by the squared sphere radius r in feet (ft).

Ev(lx) = 10.76391 × ΦV(lm) / (4⋅π⋅r(ft)2)

Calculation with area in square meters

The illuminance Ev in lux (lx) is apparently equal to the value of luminous flux ΦV in lumens (lm) which is further divided by the surface area A measured in square meters (m2).

Ev(lx) = ΦV(lm) / A(m2)

The illuminance Ev in lux (lx) is apparently equal to the luminous flux ΦV which is measured in lumens (lm) and divided by 4 times the value of pi multiplied by the squared sphere radius r measured in meters (m).

Ev(lx) = ΦV(lm) / (4⋅π⋅r 2(m2))

Lumens to candela calculator

Lumens to candela calculator

We are offering the Lumens (lm) to candela (cd) calculator to help you make calculations easy.

Lumens to candela calculator

Enter the value of luminous flux in lumens, add the value of apex angles in degrees and hit the = button to obtain the luminous intensity measured in candela.

Enter luminous flux in lumens: lm
Enter apex angle in degrees: º
   
Luminous intensity result in candela: cd

Lumens to candela calculation

For the uniform or isotropic light source, the luminous intensity Iv in candela (cd) is apparently equal to the value of luminous flux Φv in lumens (lm), which is later divided by the solid angle Ω measured in steradians (sr).

Iv(cd) = Φv(lm) / Ω(sr)

The solid angle Ω in steradians (sr) is apparently equal to twice the value of pi times 1 minus cosine of half the value of cone apex angle θ measured in degrees (º):

Ω(sr) = 2π(1 – cos(θ/2))

The luminous intensity Iv measured in candela (cd) is apparently equal to the luminous flux Φv which is measured in lumens (lm), and divided by twice the value of pi times 1 minus cosine of half apex angle θ measured in degrees (º):

Iv(cd) = Φv(lm) / ( 2π(1 – cos(θ/2)) )

So the value becomes,

candela = lumens / ( 2π(1 – cos(degrees/2)) )

Or you can say,

cd = lm / ( 2π(1 – cos(º/2)) )

Candela to lux calculator

Candela to lux calculator

The online calculator is here to help you find the Luminous intensity in candela (cd) to illuminance in lux (lx).

Candela to lux calculator

Enter the luminous intensity in candela, distance from light source, select feet or meters and press the button to get the illuminance in lux.

Enter luminous intensity in candela: cd
Enter distance and select feet or meters:
   
Illuminance result in lux: lx

Candela to lux calculation

Calculation for Candela tp lux with the distance in feet

The value of illuminance Ev in lux (lx) is apparently equal to 10.76391 times the value of luminous intensity Iv measured in candela (cd), which is later divided by the square distance from the light source d2 in the square feet (ft2).

Ev(lx) = 10.76391 × Iv(cd) / (d(ft))2

Candela tp lux calculation with the distance in meters

The illuminance Ev in lux (lx) is apparently equal to the luminous intensity Iv which is measured in candela (cd), and lastly divided by the square distance from the light source d2 in the square meters (m2):

Ev(lx) = Iv(cd) / (d(m))2

lx = 10.76391 × cd / ft2

 

Candela to lumens calculator

Candela to lumens calculator

You can easily calculate the value if calculations with our Candela (cd) to lumens (lm) calculator, check now!

Candela to lumens calculator

You all need is to enter the luminous flux measured in lumens, or the apex angle in degrees and press the = button to measure the luminous intensity in candela:

Enter Luminous intensity in candela: cd
Enter apex angle in degrees: °
   
Luminous flux result in lumens: lm

Candela to lumens calculation

For the uniform, isotropic light source, the luminous flux Φv measured in lumens (lm),  is totally equal to the luminous intensity Iv measured in candela (cd), multiplied by the solid angle Ω in the steradians (sr):

Φv(lm) = Iv(cd) × Ω(sr)

The value of solid angle Ω in steradians (sr) is apparently equal to twice the value of pi times 1 minus cosine of the half cone apex angle θ measured in degrees (°):

Ω(sr) = 2π(1 – cos(θ/2))

The luminous flux Φv  measured in lumens (lm) is apparently equal to the luminous intensity Iv measured in candela (cd), twice the value of pi times 1 minus cosine of the half apex angle θ measured in degrees (°):

Φv(lm) = Iv(cd) × ( 2π(1 – cos(θ/2)) )

So the value,

lumens = candela × ( 2π(1 – cos(degrees/2)) )

and,

lm = cd × ( 2π(1 – cos(°/2)) )

Conversion from candela to lumens

You can easily calculate the value of luminous intensity in candela (cd) to the luminous flux measured in lumens (lm). It is mandatory that you make note that you can only calculate and not convert the value of candela to lumens, since the value of lumens and candela  as they do not represent the same quantity.

Candela to lumens calculation

For the the luminous flux Φv which is measured in lumens (lm),  isotropic light source, uniform is totally equal to the value of the luminous intensity Iv which is measured in candela (cd), times the solid angle Ω which is measured in steradians (sr).

Φv(lm) = Iv(cd) × Ω(sr)

The value of solid angle Ω which is measured in steradians (sr) is equal to the twice value of pi which is later multiplied and 1 minus the cosine of half value of cone apex angle θ which is measured in degrees (°):

Ω(sr) = 2π(1 – cos(θ/2))

The luminous flux Φv which is measured in lumens (lm) is apparently equal to the luminous intensity Iv measured in candela (cd),twice multiplied the value of pi times 1 and minus cosine of half the apex angle θ measured in degrees (°):

Φv(lm) = Iv(cd) × ( 2π(1 – cos(θ/2)) )

So, the value of lumens = candela × ( 2π(1 – cos(degrees/2)) )

Or you can say,

lm = cd × ( 2π(1 – cos(°/2)) )

For Example,

Find the value of luminous flux Φv in lumens (lm), if the luminous intensity Iv in candela (cd) is 500cd and the value apex angle is 45°:

Φv(lm) = 239.13950145