I've written a simplistic Python script  that will change all of the
font-size units in an SVG file from pixels to points. The script doesn't
actually do a conversion it simply replaces the unit suffix of px with pt.
If you create some text in Inkscape with size 10 and save it; font-size:10px
Run the script on the file; font-size:10pt
Open and edit the file in Inkscape; font-size:12.5px
This is a workaround for the bug that the UI never shows the units (pixels)
associated with font size numbers and it is difficult to specify sizes in
units other than pixels . This is the quickest hack I could put together
when I realized that the text in all of the figures for my thesis was the
wrong size, therefore it hasn't been tested much, so if anybody uses it you
should take appropriate precautions (e.g. backup your data).
Clearly this is an ugly hack, but if there is no interest in fixing the
underlying issue, or it's to painful, I could put together something similar
as an effect. It seems like a better solution would be to, at a minimum show,
what unit font size is in. When setting the default font size in the toolbar
specifying a unit results in the correct conversion, so maybe a more general
fix wouldn't be to hard. Unfortunately, trying to specify a unit when
changing the size of existing text or doing anything with a unit in the text
dialog doesn't work. In any case, I would be interested in getting some input
 See bugs 161347, 1619753, and 1657337
P.S. Sorry about the cross-posting but this seems like a somewhat nonobvious
issue that has tripped up at least a few other people before me.
3203 Dead, 23,417 Wounded