UnitsML is a set of models for unambiguously encoding and identifying scientific units of measure and quantities, usable in XML and other markup languages. Developed under CalConnect TC UNITS, it enables reliable scientific data exchange across systems and disciplines.
::: info UnitsML is under active development and its documentation may change frequently. :::
Ecosystem Vision Governance History People Organizations Supporters FAQUnitsML consists of interconnected components that together form a complete system for encoding, storing, and accessing scientific units:
Authoritative XML schemas for encoding scientific units of measure — SI base units, derived units, and non-SI units. Designed to be incorporated into other markup languages.
Learn more →A comprehensive database of scientific units with detailed dimensionality information, unique identifiers, symbols, language-specific names, and conversion factors.
Learn more →A Ruby gem providing programmatic access to UnitsDB, enabling developers to integrate units data into their applications.
Learn more →- A set of models for incorporating UnitsML into any markup language or data format
- Extensive repository of schemas and information on units, quantities, and prefixes
- Designed for unit information processing — validation, conversion, and manipulation
UnitsML is developed through an open standards process:
Original standards body. TC formed in 2006, completed its mandate in 2016.
2006–2016A journey spanning over 25 years of standards development:
UnitsML has been shaped by contributors across government, academia, and industry:
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