GNU Units Manual

The units program 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;1 see Section 6.1 [Temperature Conversions], page 12. The program can also perform conversions from and to sums of units, such as converting between meters and feet plus inches.