The UDUNITS package supports units of physical quantities. Its C library provides for arithmetic manipulation of units and for conversion of numeric values between compatible units. The package contains an extensive unit database, which is in XML format and user-extendable. The package also contains a command-line utility for investigating units and converting values.


UDUNITS is typically loaded as an external dependency for R. Please ensure you select the matching GCC compiler versions of your version of R and the UDUNITS libraries.


To make this library available, run one of the following:

module load UDUNITS/2.2.26-foss-2020a
module load UDUNITS/2.2.26-GCCcore-8.3.0
module load UDUNITS/2.2.26-GCCcore-10.2.0
module load UDUNITS/2.2.28-GCCcore-11.2.0
module load UDUNITS/2.2.28-GCCcore-11.3.0

Installation notes

This section is primarily for administrators of the system.

udunits was installed using Easybuild 4.7.0, build details can be found in $EBROOTGMP/easybuild with the module loaded.


  1. Load module.

  2. Run “udunits2“.

  3. For this test we convert 5km into miles, which produces the following results:

You have: 5km
You want: miles
5 km = 3.10686 miles
x/miles = 0.621371*(x/km)