The math/gunits port

gunits-2.23p0 – GNU units conversion program (cvsweb github mirror)

Description

GNU Units converts quantities expressed in various systems of
measurement to their equivalents in other systems of measurement. Like
many similar programs, it can handle multiplicative scale changes. It
can also handle nonlinear conversions such as Fahrenheit to Celsius
or wire gauge, and it can convert from and to sums of units, such as
converting between meters and feet plus inches.

WWW: https://www.gnu.org/software/units/