In addition to @georgemk
Many devices calculates the progress and/or page counts using proprietary algorithms , so it will be rare they match between brands. (APNX is a Kindle thing and became my standard of
reference when selecting next reads in Calibre )
Count Pages Plugin is configurable and is useful to populate custom columns in Calibre with Page and Reading level stats to aid in your selections.
These do NOT affect the device.
FWIW I wish Academia would just drop the concept of PAGE and reference JUST by offset from a major division (CPW). eg. Chapter 42: Paragraph 27: Word 13
That works at any Zoom or font size.