In article , "David Biddulph" <groups [at] biddulph.org.uk wrote:
I don't think you'll find an inbuilt way of dealing with these units (in the
way you can with hours minutes and seconds), so I think your best bet would
be to put stones, pounds, and ounces in 3 separate columns, and then use a
helper column, perhaps in pounds, to combine the total, & then plot from
that column.

<can't resist ...

Better yet, simplify your life and that of those around you by using SI
units g and kg from the start. It is the standard, it's easy to use and
understand, why not use it ? :)