Search facility:  
BIPM Home | Site map | Metrology portal | KCDB | JCTLM-DB | Contact us  
Resolution 3 of the 14th meeting of the CGPM (1971)
Version française
Other Resolutions
of the 14th CGPM

Participation at the General Conference
24th meeting of the CGPM (2011): Presentations by CC Presidents
See also: Reports from CC Presidents at previous meetings of the CGPM
Resolutions of the CGPM
Proceedings of the CGPM
Chain of responsibility
Procedure for a State to become a Member of the BIPM
Procedure for a State or Economy to become an Associate of the General Conference
Evolving Needs for Metrology in Trade, Industry and Society, and the Role of the BIPM
Direct access
SI unit of amount of substance (mole)* (2) (4)

The 14th Conférence Générale des Poids et Mesures (CGPM),

considering the advice of the International Union of Pure and Applied Physics, of the International Union of Pure and Applied Chemistry, and of the International Organization for Standardization, concerning the need to define a unit of amount of substance,


  1. The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12; its symbol is "mol".
  2. When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles.
  3. The mole is a base unit of the Système International d'Unités.

Comptes Rendus de la 14e CGPM (1971), 1972, 78
Metrologia, 1972, 8(1), 36


At its 1980 meeting, the CIPM approved the report of the 7th meeting of the CCU (1980) specifying that, in this definition, it is understood that unbound atoms of carbon 12, at rest and in their ground state, are referred to.

The reader should note that the official version of this Resolution is the French text.