General Conference on Weights and Measures

The General Conference on Weights and Measures (abbreviated CGPM from the French: Conférence générale des poids et mesures) is the supreme authority of the International Bureau of Weights and Measures (BIPM), the intergovernmental organization established in 1875 under the terms of the Metre Convention through which member states act together on matters related to measurement science and measurement standards. The CGPM is made up of delegates of the governments of the member states and observers from the Associates of the CGPM. It elects the International Committee for Weights and Measures (abbreviated CIPM from the Comité international des poids et mesures) as the supervisory board of the BIPM to direct and supervise it.

Initially the work of the BIPM concerned the kilogram and the metre, but in 1921 the scope of the Metre Convention was extended to accommodate all physical measurements and hence all aspects of the metric system. In 1960 the 11th CGPM approved the title International System of Units, usually known as "SI".

The General Conference receives the report of the CIPM on work accomplished; it discusses and examines the arrangements required to ensure the propagation and improvement of the International System of Units (SI); it endorses the results of new fundamental metrological determinations and various scientific resolutions of international scope; and it decides all major issues concerning the organization and development of the BIPM, including its financial endowment.

The CGPM meets in Paris, usually once every four years. The 25th meeting of the CGPM took place from 18 to 20 November 2014, the 26th meeting of the CGPM took place in Versailles from 13 to 16 November 2018, and the 27th meeting of the CGPM took place from 15 to 18 November 2022. The 28th meeting of the CGPM will take place from 13 to 15 October 2026.

Establishment

On 20 May 1875 an international treaty known as the Convention du Mètre (Metre Convention) was signed by 17 states. This treaty established an international organization, the Bureau international des poids et mesures (BIPM), which has two governing organs:

Conférence générale des poids et mesures (CGPM), a plenary meeting of official delegates of member states which is the supreme authority for all actions;

Comité international des poids et mesures (CIPM), consisting of elected scientists and metrologists, which prepares and executes the decisions of the CGPM and is responsible for the supervision of the organization.