# Lumens to millicandela calculator

Convert luminous flux from lumens (lm) to luminous intensity in millicandelas (mcd). Ideal for LED specifications, lighting design, and beam angle calculations. Accurately convert lumens to millicandela using this convenient online tool.

## What is Lumens to millicandela

Converting lumens (lm) to millicandela (mcd) requires additional information about the beam angle or solid angle over which the light is distributed. Millicandela is a unit of measurement for luminous intensity, which describes the concentration of light within a specific solid angle.

To convert lumens to millicandela, you need to know the solid angle in steradians (sr) over which the luminous flux is distributed. The formula for this conversion is:

Millicandela (mcd) = (Luminous Flux (lm) / Solid Angle (sr)) * 1000

The result will be in millicandela.

Without the solid angle information, it is not possible to provide an accurate conversion from lumens to millicandela.

When converting between these units, it is crucial to consider the angular distribution of light from the source and the specific application requirements. Proper measurement and specification of luminous intensity require knowledge of the beam angle or solid angle over which the light is emitted.

## Lumens to millicandela calculation

For uniform, isotropic light source, the luminous intensity *I*_{v} in millicandela (mcd) is equal
to 1000 times the luminous flux Φ_{v }in lumens (lm),

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

*I*_{v(mcd)} = 1000 × *Φ*_{v(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 *I*_{v} in millicandela (mcd) is equal
to 1000 times the luminous flux Φ_{v }in lumens (lm),

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

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

So

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

Or

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

## Lumens to millicandela Example

Assuming you have a light source with different luminous flux values in Lumens (lm) and you want to convert them to Millicandela (mcd), you can use the following table:

Luminous Flux (lm) | Viewing Angle (degrees) | Luminous Intensity (mcd) |
---|---|---|

1000 | 30 | 3183.1 |

500 | 45 | 1591.6 |

200 | 60 | 636.6 |

100 | 90 | 159.2 |

To convert the luminous flux to luminous intensity, you need to divide the luminous flux by the solid angle of the viewing angle for each value.

For example, if the luminous flux is 1000 lm and the viewing angle is 30 degrees, the luminous intensity would be (1000 lm) / (30 degrees) = 3183.1 mcd.

Similarly, for a luminous flux of 500 lm and a viewing angle of 45 degrees, the luminous intensity would be (500 lm) / (45 degrees) = 1591.6 mcd.

You can follow the same calculation for other values in the table.

Please note that this conversion assumes an idealized point light source and that the light spreads uniformly within the specified viewing angle. In practical scenarios, the actual luminous intensity may vary depending on the specific characteristics of the light source and the viewing conditions.