Originally Posted by patrickt

The screen measuring standard is silly but I can't imagine you've never noticed it before. My Nexus 5 cellphone has a screen size of 4.95" but appears to be much smaller than 6" Paperwhite because the width to length ratio is different. I'm no engineer but a screen measurement diagonally is a marketing dream. I think it started with the first screen we cared about...television and has simply continued.