Short description of Excel Unit Conversion Addin 3.0: This Microsoft Add-In provides very powerful unit conversion functionality. It's tight integration with the Excel environment allows easy access through the menus and toolbars.
Units are defined in a text file, which can be modified if necessary. New derived units can be generated on the fly (e.g. kg.m/s). Dimensional Analysis is used to ensure that the conversion is legitimate. Help text and examples are supplied.