Perform unit conversions and calculations using GNU Units.
Use GNU units to perform unit conversions and calculations via the command line. Can be installed using brew and apt under "units".
Use the bash tool to run the units command. Use the -t (terse) flag to get just the numeric result.
units -t 'from-unit' 'to-unit'
Basic Conversion:
units -t '10 kg' 'lbs'
# Output: 22.046226
Compound Units:
units -t '60 miles/hour' 'm/s'
# Output: 26.8224
Temperature (Non-linear):
Temperature requires specific syntax: tempF(x), tempC(x), tempK(x).
units -t 'tempF(98.6)' 'tempC'
# Output: 37
Time:
units -t '2 weeks' 'seconds'
Rounding Output:
To round to specific decimal places (e.g. 3 places), use -o "%.3f":
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):
units '1 acre'
units supports currency (USD, EUR, etc.), but exchange rates may be out of date as they are static in the definitions file.units -t '1/2 inch' 'mm').