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Luminous Intensity Converter

Science

Convert luminous intensity between candela, kilocandela, and millicandela instantly — used for LED, lighting, and optics design specifications.

Reviewed by the thecalcu.com team · Last updated July 14, 2026

From
To
All conversionsfor 1 Millicandela (mcd)
Kilocandela (kcd)0.000001
Candela (cd)0.001
Millicandela (mcd)1
Microcandela (µcd)1000

What is a Luminous Intensity?

The Luminous Intensity Converter converts luminous intensity between candela (the SI base unit), kilocandela, millicandela, and microcandela. Luminous intensity measures how much visible light a source emits in a specific direction, one of the seven fundamental SI base units, and a key specification for LEDs, lighting fixtures, and optical components.

Enter a value in any supported unit and the converter calculates the equivalent instantly. For related light quantities, see the Luminance Converter and Illumination Converter.

Why Use a Luminous Intensity Converter?

Individual LED components are typically rated in millicandela (since their output is small), while assembled lighting fixtures or automotive headlights are rated in candela or even kilocandela, comparing a component spec against a system-level requirement, or aggregating multiple LEDs into an expected total output, requires converting between these scales accurately.

Who Should Use This Converter?

  • LED and lighting engineers converting component-level millicandela specifications against system-level candela requirements.
  • Automotive lighting designers working with headlight and indicator luminous intensity specifications across regulatory unit conventions.
  • Optics and photonics researchers converting luminous intensity data for light source characterisation.
  • Electronics hobbyists comparing LED datasheet specifications across different manufacturers.

What Insights Does the Luminous Intensity Converter Give You?

The main output is the converted value in your chosen target unit, calculated precisely from the fixed multiplier relationship between units. Because luminous intensity values range from millicandela for small indicator LEDs to kilocandela for automotive headlights, the converter helps confirm you're comparing values at a consistent, meaningful scale.

How to use this Luminous Intensity calculator

  1. Choose your starting unit from the source dropdown, for example, "Millicandela (mcd)".
  2. Enter the numeric value you want to convert in the input field.
  3. Choose your target unit from the destination dropdown, for example, "Candela (cd)".
  4. Read the converted result, which updates instantly as you type or change units.
  5. Use the swap (⇅) button if you need to reverse the conversion direction.
  6. Use the copy button to grab the result for a lighting design calculation or component comparison.
Show formula & methodology ↓Show less ↑

Formula & Methodology

The converter's base unit is candela (cd). Every supported unit has a fixed multiplier:

- 1 kilocandela (kcd) = 1,000 cd
- 1 millicandela (mcd) = 0.001 cd
- 1 microcandela (µcd) = 0.000001 cd

Any conversion follows:

Result = Input × (toBase of source unit ÷ toBase of target unit)

Worked example, converting a typical indicator LED rating of 500 mcd to candela:

Result = 500 × 0.001 = 0.5 cd

This confirms how a common LED datasheet millicandela value translates to the base candela unit used in broader lighting calculations.

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Frequently Asked Questions

What is luminous intensity?
Luminous intensity measures the amount of visible light emitted by a source in a specific direction, in units of candela, it's one of the seven SI base units and describes how bright a light source appears when viewed from a particular angle, independent of distance.
How do I convert millicandela to candela?
Divide the millicandela value by 1,000, since one candela equals 1,000 millicandela. Enter your value with 'Millicandela (mcd)' as the source and 'Candela (cd)' as the target to apply this automatically.
Why do LED datasheets often specify luminous intensity in millicandela?
Individual LEDs, especially small indicator LEDs, typically have luminous intensity values well under 1 candela, so millicandela keeps the numbers in a more readable range, a typical indicator LED might be rated at a few hundred to a few thousand millicandela.
What is the difference between luminous intensity and luminance?
Luminous intensity (candela) measures the total light output from a source in a specific direction, while luminance (candela per square metre) measures that intensity spread over the visible surface area of the source, luminance accounts for how large or small the emitting surface appears. See the [Luminance Converter](/luminance-converter/) for that related quantity.
How does luminous intensity relate to illumination (lux)?
Illumination (lux, measuring light falling on a surface) depends on both the light source's luminous intensity and its distance from the surface, following an inverse-square relationship, a light source's candela rating alone doesn't tell you how brightly lit a specific surface will be without knowing the distance. See the [Illumination Converter](/illumination-converter/) for that related quantity.
What is a typical candela rating for common light sources?
A standard candle historically defined roughly 1 candela (hence the unit's name), a typical household LED bulb might be rated at several hundred to over a thousand candela in its brightest direction, and a car headlight can reach tens of thousands of candela.
Why is candela defined as an SI base unit rather than derived from other units?
Candela is one of the seven SI base units because it's tied to the specific physiological response of human vision (photopic luminous efficiency) rather than being purely derivable from mechanical or electrical quantities, requiring its own independent definition.
How is luminous intensity measured for an LED or light source?
Luminous intensity is typically measured using a photometer or goniophotometer, which captures the light output at a specific angle and distance, then calculates the candela value accounting for the inverse-square relationship between measured illuminance and distance.
Does luminous intensity vary by viewing angle for the same light source?
Yes, most light sources don't emit uniformly in all directions, so luminous intensity is typically specified either as a peak value (brightest direction) or as a full angular distribution, which matters significantly for LED and spotlight applications where directional output is the whole point.
What industries commonly need luminous intensity unit conversion?
LED and lighting manufacturing (component specification and quality control), automotive lighting (headlight and indicator design), and optics and photonics research all routinely work with luminous intensity data, often needing conversion between millicandela component specs and candela or kilocandela system-level ratings.
Also known as
candela convertermillicandela to candela converterled luminous intensity converterluminous intensity unitskcd to cd converter