Microsoft 365 (Word) Paper Sizes

Today, I measured what is supposed to be 8.5" X 11" paper using an online ruler and found that my paper and padfolio sizes do not make sense. 

For example, my padfolio is actually 8.5'' H X 6.5" W based on the onscreen ruler.  The printer paper I have bought states 8.5" X 11" but it is actually 7.5" H X 5 3/4 " W based on the onscreen ruler.  Of course, the monitor is at a 100% and is supposedly 32 inches but only maps out to 18 3/4 according to the onscreen ruler.

Therefore, I would like to know what the exact paper sizes are for Microsoft 365's 8.5" X 11" paper settings in both the web and desktop version.