For a submission requirement I need that my document exactly fills a box of m x n inches.
Does anybody know how I can specify this in LaTeX?
In your document preamble, use
\usepackage[includeheadfoot,width=<m>in,height=<n>in]{geometry}
where you specify <m>
and <n>
(or use text={<m>in,<n>in}
). Add the showframe
option to see the boundaries.
geometry
is the go-to layout package.