Weights & Measures by Charlie Brown (Updated for the Commodore 64 by Donna W. Woody) - This is a really handy tool!  Here's a short description taken from the first part of the documentation which is in the archive:

This program will replace a whole reference library on weights and measures. Menu driven and easy to use, it allows you to convert between any two weights, volumes, lengths, areas, or rates.

Do you want to know how many teaspoons are in a gallon? Now your C-64 can tell you in a flash--- every weight and measure you can think of is included in the table. WEIGHTS & MEASURES is an invaluable tool for dealing with those "important to know, but hard to remember" conversions. But some of the conversions aren't used that much anymore--- you may have to get out a dictionary to find out what some of them are!