GNU Units Skill

Use GNU units to perform unit conversions and calculations via the command line. Can be installed using brew and apt under "units".

Usage

Use the bash tool to run the units command. Use the -t (terse) flag to get just the numeric result.

bash

units -t 'from-unit' 'to-unit'

Examples

Basic Conversion:

bash

units -t '10 kg' 'lbs'
# Output: 22.046226

Compound Units:

bash

units -t '60 miles/hour' 'm/s'
# Output: 26.8224

Temperature (Non-linear): Temperature requires specific syntax: tempF(x), tempC(x), tempK(x).

bash

units -t 'tempF(98.6)' 'tempC'
# Output: 37

Time:

bash

units -t '2 weeks' 'seconds'

Rounding Output: To round to specific decimal places (e.g. 3 places), use -o "%.3f":

bash

units -t -o "%.3f" '10 kg' 'lbs'
# Output: 22.046

Definition Lookup: To see what a unit definition is (without converting), omit the second argument (without -t is more verbose/useful for definitions):

bash

units '1 acre'

Notes

•Currency: units supports currency (USD, EUR, etc.), but exchange rates may be out of date as they are static in the definitions file.
•Safety: Always quote your units to prevent shell expansion issues (e.g. units -t '1/2 inch' 'mm').