A4?? Letter??

https://answers.launchpad.net/ubuntu/+source/evince/+question/6846

This is because evince uses the value of the LC_PAPER locale setting, for en_US.UTF-8 this defaults to letter.
You can override this setting by using an LC_PAPER environment variable, if you want to do the change system wide you can add LC_PAPER="en_GB.UTF-8" (defaults to A4) to /etc/environment and log out and back into GNOME.
Pascal De Vuyst said on 2007-05-22:


Many thanks indeed, Pascal! I added

export LC_PAPER="en_GB.UTF_8"

to ~/.profile and it works perfectly! It is a little bit weird that evince
determines the paper SIZE from a COUNTRY setting (and not from
a size setting, like the one in /etc/papersize). In my opinion, this
should be changed in future.

Best regards

Carniolian