Meaning & use
candela
Last updated
Meanings
nouncountabletechnicalphysics
The standard unit of luminous intensity, measuring how strong a light source appears in one particular direction.
Grammar: Countable and usually used with numbers: a 100-candela lamp, several candelas.
Patterns
- a light of X candelas
- X candelas per square meter
The lamp is rated at 1,200 candelas, bright enough to light the whole yard.
Engineers measured the beam at 500 candelas at its center.
A single candle gives off roughly one candela in most directions.
nounsingulartechnicalphysics
The base unit of light intensity in the International System of Units, defined from a fixed physical constant.
Grammar: Often used as the unit name after a number, and usually singular in that position: 20 candela, not 20 candelas.
Patterns
- measured in candela
- the candela is defined as
Since 2019 the candela has been defined using a fixed numerical value.
Luminous intensity is expressed in candela in physics textbooks.
Word forms
| plural | candelas |
|---|
Common combinations
- measured in candelas
- The brightness of the display is measured in candelas.
- candela per square meter
- Screen luminance is often given in candelas per square meter.
- a beam of X candelas
- The spotlight produces a beam of 2,000 candelas.
- the candela is defined as
- The candela is defined as a fixed amount of luminous intensity.
Synonyms and how they differ
- candlepower
- An older, non-metric term for much the same idea; it survives in everyday descriptions of lamps and torches.
- lumen
- Measures total light given out in all directions, while a candela measures intensity in one direction.
- lux
- Measures how much light falls on a surface, not how strong the source is.
Word family
- candle noun
- A stick of wax with a wick that burns to give light; the candela's name comes from it.
Commonly confused: candela or candle? candela or lumen?
candela vs candle
A candle is the wax object you burn; a candela is a scientific unit of light intensity.
candela vs lumen
Learners often mix these up: a lumen is total light output, a candela is intensity in one direction.
Practice
Which sentence uses 'candela' correctly?
Choose one answer.
A candela measures light intensity in a direction, so it fits the pointed bulb. Option 1 confuses it with energy use, option 2 describes light falling on a surface (lux), and option 3 treats it as a physical object like a candle.
Make it your own
Write a sentence using “candela”, then check it and compare it with the examples above.