For version 1.7:
Unit conversion toolbar is shown on the picture:
Use the toolbar for conversion units of measurement of a category.
It is very simple! Select a category in that you need to convert units. In the second list select a system, from that you want to convert. Further, select base unit, target system and target unit.
Example:
For example, let's convert meters to feet of the USA unit system:
Now change the value of the meters:
The value of the feet is changed also.
On the same document you can convert another units. Read more »