UOMs

Units of measure (UOMs) are standardized quantities used to express the magnitude of a measurement. They provide a consistent way to describe how much of something is being measured, enable arithmetic operations, and support clear communication and data exchange across organizations and regions. A UOM specifies the kind of quantity (such as length, mass, or time) and the scale on which it is measured, while the numeric value represents the amount.

UOMs are categorized into base units, derived units, and non-SI or domain-specific units. In the International System of Units (SI), base units include meter, kilogram, second, ampere, kelvin, mole, and candela. Derived units combine base units, such as speed (meter per second), area (square meter), and volume (cubic meter). Many industries also use non-SI units, such as inches, pounds, and gallons, and some domains adopt specialized units like barrels or bushels. Some quantities are dimensionless, such as ratios or percentages.

Standards and coding systems support interoperability. SI and ISO 80000 define formal unit definitions, while systems like UCUM (Unified Code for Units of Measure) provide machine-readable codes for health care and other domains. In data management and manufacturing, UOMs are managed in catalogs with conversion factors to enable accurate conversions between units. Practices include storing both the numeric value and its UOM, ensuring consistent use within datasets (for example, BOMs, pricing, and inventory), and carefully handling units that affect temperature or other compositional scales.

Effective use of UOMs reduces ambiguity, prevents errors, and supports reliable measurements, calculations, and reporting.