Term: base quantity
https://doi.org/10.1351/goldbook.B00609

Definition:
One of the quantities that, in a system of quantities, are conventionally accepted as functionally independent of one another. In the SI, these are: length, mass, time, electric current, temperature, amount of substance, and luminous intensity. All other physical quantities (and units) are regarded as being derived from these base quantities (and base units).

Related Terms:
1) length (http://doi.org/10.1351/goldbook.L03498).
2) mass (http://doi.org/10.1351/goldbook.M03709).
3) time (http://doi.org/10.1351/goldbook.T06375).
4) electric current (http://doi.org/10.1351/goldbook.E01927).
5) temperature (http://doi.org/10.1351/goldbook.T06321).
6) amount of substance (http://doi.org/10.1351/goldbook.A00297).
7) luminous intensity (http://doi.org/10.1351/goldbook.L03647).
8) base units (<em>of measurement</em>) (http://doi.org/10.1351/goldbook.B00610).

Source: PAC, 1986, 58, 1405. 'Recommendations for the presentation of thermodynamic and related data in biology (Recommendations 1985)' on page 1406 (https://doi.org/10.1351/pac198658101405)

Citation: 'base quantity' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.B00609

License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.

Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.