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cdv3rev 12026-03-17INTERNATIONAL BUREAU OF WEIGHTS AND MEASURES (BIPM); The International System of Units (SI) - 9th editon 2019

candela

0112/2///62720#UAA370

SI unit of Iuminous intensity in a given direction defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, to be 683 when expressed in the unit lm W-1, which is equal to cd sr W-1, or cd sr kg-1 m-2 s3, where the kilogram, metre and second are defined in terms of h, c and ∆νCs

unit

All properties21#

Version
3
Revision
1
Preferred name
candela
Short name
cd
Definition
SI unit of Iuminous intensity in a given direction defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, to be 683 when expressed in the unit lm W-1, which is equal to cd sr W-1, or cd sr kg-1 m-2 s3, where the kilogram, metre and second are defined in terms of h, c and ∆νCs
Definition source
INTERNATIONAL BUREAU OF WEIGHTS AND MEASURES (BIPM); The International System of Units (SI) - 9th editon 2019
Note
Base unit of the International System of Units (SI)
Unit structure
cd¹
Unit in text
candela
Unit in SGML/XML
Structured markup (math)(122 chars)
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <!-- UAA370 --> <mi mathvariant="normal">cd</mi> </math>
UN/ECE code
CDL
Unit conversion
Structured markup (UnitsML)(503 chars)
<UnitsML xmlns="https://schema.unitsml.org/unitsml/1.0"><Unit xml:id="0112/2///62720#UAA370"><Conversions><Float64ConversionFrom xml:id="UAA370_from_UAA370" initialUnit="0112/2///62720#UAA370" multiplicand="1" divisor="1" exact="true" /></Conversions></Unit><Unit xml:id="https://si-digital-framework.org/SI/units/candela"><Conversions><Float64ConversionFrom xml:id="SI::candela_from_UAA370" initialUnit="0112/2///62720#UAA370" multiplicand="1" divisor="1" exact="true" /></Conversions></Unit></UnitsML>
Responsible committee
IEC/SC 3D
Publisher
IEC
Published in
IEC 62720
Status level
Standard
Version release date
2026-03-17
Revision release date
2026-03-17
Version initiation date
2026-03-17
Change request ID
C00192