# Paper size specification in a LaTeX style file

I need to change the paper size on the attached style file. The file seems to be for the European A4 paper size, and I need to change it to the US letter size (8.5 x 11 in.). Which line in this file refers to the paper size and how do I change it?

\def\ps@sepone{%
\def\@oddfoot{\hfil\it\sepfoot\hfil}
\def\@evenfoot{\hfil\it\sepfoot\hfil}}
\def\ps@sep{%
\def\@oddfoot{\hfil\it\sepfoot\hfil}
\def\@evenfoot{\hfil\it\sepfoot\hfil}}
\pagestyle{sep}
\def\footer#1{\def\sepfoot{#1}}
\footer{}
\thispagestyle{sepone}
\def\makefootline{\baselineskip24\p@\line{\the\footline}}

\newfont{\bigbf}{cmbx10 scaled\magstep 3}
\newfont{\bigit}{cmti10 scaled\magstep 1}
\newfont{\bigrm}{cmr10 scaled\magstep 1}

\textheight=9in
\textwidth=6.4in
\textfloatsep 30pt plus 3pt minus 6pt
\parskip=5pt
\oddsidemargin=-.2in
\voffset=-.1in
\newdimen\singlespacing
\singlespacing=11pt     % single line spacing
\normalbaselineskip=15pt     % 1.5 line spacing
\baselineskip=\normalbaselineskip

% multi-line title
\newenvironment{SEPtitle}{\begin{center}\bigbf}{\end{center}}
\def\title#1{
\begin{SEPtitle}
\vbox{\baselineskip=1.5\normalbaselineskip
\vskip1in #1\vskip.3in}
\end{SEPtitle}}
% multi-line author
\newenvironment{SEPauthor}{\begin{center}\bigit}{\end{center}}
\def\author#1{
\begin{SEPauthor}
\vbox{#1 \vskip.3cm}
\end{SEPauthor}}
\newenvironment{SEPauthoraff}{\begin{center}\bigrm}{\end{center}}
\def\authoraff#1{
\begin{SEPauthoraff}
\vbox{#1 \vskip.2in}
\end{SEPauthoraff}}
\vbox{\vskip.3in #1}\nopagebreak
\vbox{\vskip.2in #1}\nopagebreak

% define ABSTRACT, INTRODUCTION, DISCUSSION, CONCLUSIONS, REFERENCES,
% and APPENDIX as the first three letters

% reference macro, second ... lines are indented
\newdimen\dtmp     % temporary dimension variable
\def\reference#1{ \baselineskip=\singlespacing \dtmp=\hsize
\advance\dtmp by-\parindent \parshape 2 0in \hsize \parindent
\dtmp \noindent #1 \endgraf \baselineskip=\normalbaselineskip
\vskip4pt
}

\newcommand{\bs}{$\backslash$}
\def\under{\underline}
\def\dotdot{\ddot}
\def\nwl{\hfill\break}      % similar to latex's \newline but does not
% complain if there is no line to break
\def\ind#1{\par\everypar{\hangindent=#1\hangafter=0\hskip-\parindent}}
\def\tmpind#1{\par\hskip#1}
\newenvironment{SEPcntr}{\begin{center}}{\end{center}}
\def\cntr#1{\begin{SEPcntr} #1 \end{SEPcntr}}
% displayed text, indented, justification off
\def\displaybegin{\par\begingroup\medskip\narrower\narrower\noindent
\obeylines\obeyspaces}
\def\displayend{\endgroup\smallskip\noindent}
% fill and nofill
\def\nofill{\par\begingroup\noindent\obeylines\obeyspaces}
\def\fill{\endgroup\noindent}

% define a boxing macro
\def\boxit#1{\vbox{\hrule\hbox{\vrule\kern10pt\vbox{\medskip\kern5pt#1\bigskip
\kern5pt}\kern10pt\vrule}\hrule}}
• Welcome to TeX.SX! \RequirePackage[letterpaper]{geometry} at the beginning of your .sty file might help. The \textheight gives some clue, but not the papersize – user31729 May 13 '15 at 21:25
• By the way: Your document above is a little-bit orphan... we don't know what's the exact purpose of it. – user31729 May 13 '15 at 21:35
• The units are in inches, not in centi- or millimetres. – Bernard May 13 '15 at 21:43
• I can not see any specification of paper size. You can prepend \paperheight=11in \paperwidth=8.5in – touhami May 13 '15 at 22:06