# Lumens to millicandela calculator

Lumens (lm) to millicandela (mcd) calculator and how to calculate.

### Lumens to millicandela 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 flux in lumens: lm Enter apex angle in degrees: ° Luminous intensity result in millicandela: mcd

#### Lumens to millicandela

It is a conversion calculator that is used to convert the luminous flux in lumens (lm) to the luminous intensity in Millicandela (mcd). It uses a simple program in executing the calculations making it an effective online calculator. The initial step is to enter the value of the luminous flux in lumens. Proceed to the next text field where you enter the apex angle in degrees. Afterwards, click on the ‘Calculate’ button to execute the conversion. To perform new calculations, you will use the ‘Reset’ button to clear the previous calculations from the text fields. The luminous intensity result in Millicandela will be displayed in the bottom platform of the calculator below the two controls.

#### For example;

Determine the luminous intensity in Millicandela if the luminous flux in lumens is 324 (lm) and the apex angle in degrees is 65°.

First, you need to enter 324 in the luminous flux in lumens text field and 65 as the apex angle in degrees respectively. Afterwards, click on the ‘Calculate’ button. The luminous intensity result in Millicandela will be displayed as; 329268.10307 (mcd).

This calculator uses particular formulas in executing the calculations

For uniform, isotropic light source, the luminous intensity Iv in millicandela (mcd) is equal to 1000 times the luminous flux Φv in lumens (lm),

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

Iv(mcd) = 1000 × Φv(lm) / Ω(sr)

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 intensity Iv in millicandela (mcd) is equal to 1000 times the luminous flux Φv in lumens (lm),

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

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

So

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

Or

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