TBH I nearly asked for a word count but I thought that might be imposing having already asked for a page count.
Story is this: a long time ago (2007) I started a project to re-read all the Harry Potter books before the final one came out. In order to do so in time I had to set pretty ambitious targets as I'd left it late. So I wrote myself a spreadsheet to track my progress. I soon discovered I averaged 60 pages/hour.
Now I use what may be considered the great-grand-daughter of that spreadsheet to track my reading. And although I do track word count, most of the spreadsheet still refers to pages. Trouble is I rarely read on paper any more. So I tend to get the page count of the paperback edition from Amazon and use that. I have a section of the spreadsheet where I can enter all the different measures (Kindle pages, locations, epub page numbers, calibre locations etc) and convert between them. This also allows me to switch between different methods of reading the same book and still record in a common format - pages.
So 'pages' is a bit of a problematic measure for estimating time to read. OTOH word count, whilst better in terms of a measure of the size of the book, isn't necessarily better for time estimates because reading pace can vary with the content of the book, how I'm enjoying it, how easy the language is etc.
For example of the 16 books I've read this year so far, the words/page varies from 206-386 with an average of 281. So the size of a page varies a lot. But my words/min reading pace varies from 179-247, average 211 - which is almost as much variability.
I get a better estimate once I've started reading the book because then I can calculate a rate based on the current book only.
Sorry for rambling, some of you might be interested, some will probably be repulsed by the very idea
Oh and I just got the email to say Making History is now on loan to me!