UnitsML

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Unambiguous models for scientific units of measure

UnitsML provides a set of models for unambiguously encoding and identifying scientific units of measure and quantities — usable in XML and other markup languages, improving interoperability across information systems and scientific disciplines.

Learn about UnitsML Explore UnitsDB

Browse UnitsDB

Explore the complete database of 380+ units, 199 quantities, 92 dimensions, and more — all with interactive search, cross-linking, and JSON-LD downloads.

380 Units199 Quantities92 Dimensions33 Prefixes7 Systems
Open UnitsDB
mmetreL
kgkilogramM
NnewtonL·M·T⁻²
PapascalL⁻¹·M·T⁻²
JjouleL²·M·T⁻²
WwattL²·M·T⁻³

The UnitsML Ecosystem

An integrated suite of schemas, databases, and tools for encoding scientific units of measure.

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How UnitsML Works

Three steps to unambiguous unit encoding in scientific data.

XML
<UnitsML xmlns="https://schema.unitsml.org/unitsml/1.0">
  <UnitSet>
    <Unit xml:id="m" dimensionURL="#L">
      <UnitName>metre</UnitName>
      <UnitSymbol>SI</UnitSymbol>
    </Unit>
  </UnitSet>
</UnitsML>

Schemas

UnitsML XML Schemas (XSD) and UnitsDB YAML schemas for encoding units of measure.

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Software

Ruby gems and libraries for programmatic access to UnitsDB and UnitsML data.

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Learn

Understand what UnitsML is, how it works, and how to incorporate it into your projects.

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