Millicandela to Lumens Calculator
Convert millicandela to lumens from the beam angle: lumens = mcd / 1,000 × solid angle. Formula, worked example and a table for LED data sheets.
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Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.
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Formula
Worked example
| Input | Value |
|---|---|
| Luminous intensity (mcd) | 5,000 |
| Full beam angle (°) | 30 |
- Ω = 2π × (1 − cos(30° / 2)) = 0.21409 sr
- I = 5,000 mcd / 1,000 = 5 cd
- Φ = I × Ω = 5 × 0.21409 = 1.0705 lm
Typical values
| Luminous intensity (mcd) | Luminous flux (lm) |
|---|---|
| 500 | 0.107 |
| 1,000 | 0.214 |
| 5,000 | 1.07 |
| 10,000 | 2.141 |
| 20,000 | 4.282 |
Other inputs are the same as in the worked example above.
Assumptions
- Intensity is the same everywhere inside the cone
- No light outside the cone
Data-sheet millicandela is normally the peak on-axis value, so the flux from this conversion is an upper estimate. Use the total luminous flux on the data sheet where it is given.
Frequently asked questions
How do I convert Millicandela to Lumens?
Ω = 2π × (1 − cos(θ / 2)); Φ (lm) = I (cd) × Ω; I (mcd) = Φ / Ω × 1,000. Worked example: Luminous intensity (mcd) 5,000, full beam angle (°) 30 gives 1.07 lm.
What do I need to enter?
Enter luminous intensity (mcd), luminous flux (lm) and full beam angle (°). Leave blank the value you want to find, and the form solves for it.
What is a millicandela?
A millicandela (mcd) is one thousandth of a candela, the unit of luminous intensity. LED data sheets quote small indicator LEDs in mcd, usually as the peak value on the axis of the beam.
Why does the beam angle matter?
Candela is light per steradian and lumens is the total light, so the beam angle sets the solid angle that links them. A narrow beam concentrates the same lumens into more millicandela. Use the full angle between the half-intensity points, not the half angle.
How accurate are the results?
Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.
Related
Next steps in a design: Lumens to CandelaCandela to Lux
Opposite direction: Lumens to Millicandela
Also see: Lumens to Lux Lux to Lumens Lumens to Candela Candela to Lumens
Formula guides: Lighting Formulas: Lux, Lumens and CandelaLED Formulas: Resistor Value and Power
All 78 conversionsMillicandela and Lumens from Beam Angle in Elecmetric