Unit Conversion

Convert numbers between two units quickly and precisely

Luminous Intensity

Unit Conversion

Convert luminous intensity: candela, candlepower, and Hefner candle

Luminous intensity states how intensely light is emitted in a specific direction and is stated in candela (cd), the SI unit, as well as kilocandela (kcd) for very bright sources. Candlepower (cp) and the Hefner candle (HK) are also historically common.

Key conversion factors:

  • 1 kilocandela (kcd) = 1,000 candela (cd)
  • 1 candlepower (cp) ≈ 1 candela – historically roughly equivalent
  • 1 Hefner candle (HK) ≈ 0.903 candela

Applications:

  • Lighting technology: directional characteristics of spotlights and projectors
  • Safety technology: range of signal lamps and beacons

The luminous intensity converter supports comparing directional light sources by their beam characteristics. For the brightness of a surface as seen by an observer, use the luminance converter.

Frequently asked questions about converting luminous intensity

Luminous flux (lumen) describes the total amount of light a source emits in all directions. Luminous intensity (candela), on the other hand, describes how intensely the light is concentrated in a specific direction – important for directional light sources like spotlights.

The Hefner candle (HK) was a historical unit of luminous intensity based on a standardized amyl acetate flame, used before the modern candela definition. 1 Hefner candle equals about 0.903 candela.

Candlepower (cp) and candela (cd) are historically almost equivalent and are treated as approximately equal in this converter. Candela is the modern, precisely defined SI unit, while candlepower is an older, less precise predecessor term.