ISO 80000-1:2022

Overview

ISO 80000-1:2022 - Quantities and units, Part 1: General provides the foundational definitions and principles for expressing physical quantities, units, symbols and coherent unit systems. It defines the International System of Quantities (ISQ) that underpins the International System of Units (SI) and supplies general guidance intended for broad use across science, engineering and technology. The standard is a second edition (2022) and serves as an introduction to other parts of the ISO/IEC 80000 series.

Key topics and technical requirements

ISO 80000-1:2022 covers core conceptual and editorial requirements rather than detailed tabulations of unit values. Major topics include:

• Concepts and definitions
  • What constitutes a quantity; distinction between general quantities and individual instances.
  • Systems of quantities: base quantities and derived quantities.
• International System of Quantities (ISQ)
  • The special choice of base quantities (length, mass, time, electric current, thermodynamic temperature, amount of substance, luminous intensity) and their relations.
• Constants
  • Treatment of universal (fundamental) constants and empirical constants; role of constant multipliers and numerical factors in quantity equations.
• Dimensions and quantity equations
  • Dimensional analysis, quantity equations and coherent unit systems.
• Units, symbols and numerical values
  • Rules for expressing units and numerical values, including coherent units and the relationship between quantities and their numerical representations.
• Printing and notation rules
  • Conventions for symbols, subscripts, combined symbols, expressions for dimensions, numbers, decimal sign, multiplication/division, and notation for uncertainty.
• Supporting material
  • Normative annexes (specific terms for quantities; rounding rules) and bibliography.

(The standard explicitly does not cover ordinal quantities and nominal properties.)

Practical applications and target users

ISO 80000-1:2022 is a foundational reference for anyone who needs consistent, internationally-aligned expression of physical quantities and units. Typical users include:

• Metrologists and calibration laboratories
• Standards developers and technical committees
• Engineers and designers documenting specifications
• Scientific publishers and authors preparing manuscripts, data tables and formulas
• Software developers implementing unit-aware calculations and data models
• Educators preparing curricula in physics, engineering and applied sciences

Using ISO 80000-1 improves interoperability, reduces ambiguity in technical communications, and supports correct unit handling in calculations, documentation and data exchange.

Related standards and references

• ISO/IEC Guide 99 - International vocabulary of metrology (VIM)
• BIPM - The International System of Units (SI Brochure, 9th ed., 2019)
• Other parts of the ISO/IEC 80000 series and IEC/TC 25 publications

Keywords: ISO 80000-1:2022, quantities and units, ISQ, International System of Quantities, SI, units, symbols, dimensions, coherent unit systems, quantity equations.