Common UCUM units

At first glance, the Unified Code for Units of Measure (UCUM) may seem pretty complex. But for most of the units you use, the UCUM representation is pretty recognizable. And, for many simple units the UCUM syntax is actually the same string as what you currently use. To help get you going, we’ve created this translation table that enumerates the UCUM syntax for many common unit patterns currently used in electronic reporting.

We composed an early version that focused on the basics. It was based on content provided by Intermountain Healthcare, from a joint National Library of Medicine and Regenstrief Institute project analyzing raw units from more than 23 laboratory sources, and from the HL7® table of units. We excluded the units of measure for which we couldn’t find clear definitions or patterns of usage, those we believed would only be used in pharmacy dispensing, and units used for purely clinical reporting (e.g. cigarette pack-years). We have included most of the pure metric units from our sources, whether or not they apply directly to lab testing because they will be generally useful—and are pretty straightforward in UCUM.

The process used to generate this table is described in the file preface. We have made several iterative improvements in new versions.


License and copyright

These files are bound by the LOINC License. Copyright © 1995-2022, Regenstrief Institute, Inc. All rights

File metadata


The files are available for download from GitHub and included in the full UCUM package.

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