Millicandela (mcd) to Lumens Converter

Convert millicandela (mcd) to lumens using LED viewing angle, luminous intensity, beam angle, solid angle, and optical parameters for accurate LED lighting calculations.

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Intensity (Luminous)

mcd

Angle (Beam)

Please enter all required numeric values.

RESULTS

Luminous Flux

Solid Angle

Input Parameters Specification

Luminous IntensityEnter LED intensity in millicandela, usually written as mcd in LED datasheets.

Beam AngleEnter the full viewing angle or beam angle in degrees.

Solid AngleThe calculator derives solid angle in steradians from the entered beam angle.

Luminous FluxThe final result is total visible light output in lumens.

Practical Operational Examples

Narrow LED

A high mcd LED with a narrow beam may look very bright straight ahead but may produce fewer total lumens.

Wide Angle LED

A wider beam spreads light over a larger solid angle, so the same mcd value can convert to more lumens.

Diagrams & Theory

This original SVG shows how millicandela intensity and beam angle form a light cone, then convert into luminous flux using solid angle.

Formulas & Mathematical Logic

Ω = 2π × (1 − cos(θ × π / 360))

Luminous Flux = Intensity × Ω / 1000

Intensity is entered in mcd, so it is divided by 1000 to convert millicandela into candela before getting lumens.

Step-by-Step Example

Example: Intensity = 12000 mcd and beam angle = 30°.

Ω = 2π × (1 − cos(30 × π / 360)) = 0.214094 sr.

Lumens = 12000 × 0.214094 / 1000 = 2.569128 lm.

How to Use This Calculator

Enter the LED luminous intensity value in mcd.

Enter the beam angle from the LED datasheet.

Click Calculate.

Read luminous flux in lumens and solid angle in steradians.

About This Calculator

Convert LED mcd rating into usable lumen output.

This MCD to Lumens Converter helps compare LEDs more realistically by including beam angle and solid angle.

Many LED datasheets list brightness in mcd, but lighting projects often need lumens. Millicandela describes luminous intensity in one direction, while lumens describe total luminous flux. That means a narrow-beam LED and a wide-beam LED can have the same mcd rating but very different lumen output. This calculator uses beam angle to estimate the solid angle and then converts mcd into lumens.

mcdMillicandela is directional luminous intensity.

lumensLumens represent total visible light output.

beam angleA wider beam increases solid angle.

LED comparisonUse lumens when comparing total light output.

Tip: Always use the LED datasheet beam angle. Guessing the angle can change the lumen result a lot.

Frequently Asked Questions

What is mcd?

mcd means millicandela. It is one-thousandth of a candela and measures directional luminous intensity.

What is a lumen?

A lumen measures total visible light output from a source.

How does beam angle affect lumens?

A wider beam covers a larger solid angle, so the same mcd value can convert into more lumens.

Why can two LEDs with the same mcd have different lumens?

Because beam angle changes how much total light is spread into space.

What is solid angle?

Solid angle is a 3D angle measured in steradians. It describes how wide the light cone is.

Is mcd the same as candela?

No. 1000 mcd equals 1 candela.

Can I compare LEDs using lumens?

Yes. Lumens are better for comparing total light output.

Does beam angle change perceived brightness?

Yes. Narrow beams can look brighter in one direction, while wide beams spread light over more area.

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About this tool

Millicandela (mcd) to Lumens Converter is a free online calculator tool. Use it to get instant, accurate results for your electronics calculations.