# 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: ° 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 (°):

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 (°) 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(°/2)) ) / 1000