Paper and notebook sizes are an unfortunately confusing thing. You just want some printer paper or a new notebook, and instead you are choosing between “A4” and “B5” and a slew of other sizes that mean nothing to you. Maybe you are better off switching to numbers, like “8.5 by 11” but we’ve all made the mistake of ordering legal paper when we meant to get normal copy paper!
This guide should help you sort out all your loose leaf paper and notebook size problems.