[texhax] source of LaTeX doc default sizes?

[Hefferon, James S.]

I am looking for the default sizes of LaTeX documents.  I would like to know at least the margins (left and right, for odd and even pages, and for all default paper sizes) for article 10, 11, 12, book 10, 11, 12, etc.  

For instance, I see the computations in bk10.clo.  I could go through them myself of course but I was hoping there was a source that had reliably done it already.  Does anyone know of one?

Thank you,
Jim