Originally Posted by HarryT
Exactly. A4 is a little bit "taller" and a little bit "narrower" than US Letter, but they are pretty much interchangeable. Provided they have reasonable margins, you can print an A4 page on a "Letter"-sized piece of paper, and vice versa, without truncating any of the text.
It would make life easier if the US would adopt the same measurement systems that the rest of the world uses
You do know that the rest of the world is wrong. US Letter is what should be adopted.