Millicandela to lumens calculator

Millicandela (mcd) to lumens (lm) calculator and how to calculate.

Millicandela to lumens calculator

Enter the luminous flux in lumens, apex angle in degrees and press the Calculate button

to get the luminous intensity in millicandela:

Enter Luminous intensity result in millicandela: mcd
Enter apex angle in degrees: º
   
luminous flux result in lumens: lm

Lumens to millicandela calculator ►

Millicandela to lumens calculation

For uniform, isotropic light source, the luminous flux Φv in lumens (lm) is equal to the luminous intensity Iv in millicandela (mcd),

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

Φv(lm) = Iv(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 (º):

Ω(sr) = 2π(1 - cos(θ/2))

 

The luminous flux Φv in lumens (lm) is equal to the luminous intensity Iv in millicandela (mcd),

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

Φv(lm) = Iv(mcd) × ( 2π(1 - cos(θ/2)) ) / 1000

So

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

Or

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

 


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