I track by number of books, but I also find it interesting to check the page cpunt stats on Goodreads at times.
Right now, for this year, my 11 books read - which includes a short story counted as a separate read - come to 4061 pages (based on page counts entered for the editions I picked as read on GR, which are mostly ebook or Kindle editions with page counts similar to paper books), which means a ~370 page average - in other words, I don't need to feel bad about counting the odd short story separately as it does, indeed, even out.
My last year's stats were 136 books / 45,237 pages, which comes to ~332 pages per book; again, I read about ten short stories, but my overall reads averaged out nicely to 136 perfectly average novel sized books. (Also, it might be that some of my last year's reads were entered as ebooks that don't have a page count added in GR database; I didn't start to pay attention to that until late in the year and in some cases I went back and switched to an e-edition that did have a page count - but I couldn't be bothered to go and check all 136 books.)
ETA: Actually, I just realised the short story I read didn't even have a page count entered. And I found the setting on Goodreads that displays number of pages in My Books, so now I can easily go back and check for the no-page-count books I read, and as I'm a librarian, I can go and add the page counts to the editions when I can find them on Amazon / publisher site.
