This is an AutoLISP program for converting quantities from a unit to another unit, implemented with a DCL dialogue.

This version supports units of time, units of length, units of area, units of volume, units of mass, circular measure and solid measure.

Select the source unit in the popup list named: Original Unit (an interesting feature: if you select the main metric unit, the items in the popup list change from all the units to the metric unit with prefixes and vice versa).

You obtain the converted value in the corresponding box. This value is returned to AutoCAD.
ALLUNITS can be used transparently within an AutoCAD command (such as OFFSET, CIRCLE [for radius, diameter], etc.).