What would the equivalent \setlength commands be for letter and A4 paper?

Question

If one were type setting a business letter on A4 paper he might use:

\setlength{\textheight}{215mm}
\setlength{\textwidth}{160mm}
\setlength{\oddsidemargin}{0pt}
\setlength{\topmargin}{-20pt}
\setlength{\headsep}{35pt}
\setlength{\textwidth}{160mm}
\setlength{\evensidemargin}{0pt}
\setlength{\headheight}{12pt}

Is this correct for A4 size paper? And what would the measurements be for letter paper?

Answer 1

You can use the layout package to retrieve the lengths:

\documentclass[a4paper]{article}
\usepackage{layout}

\begin{document}

\layout

\end{document}

and

\documentclass[letterpaper]{article}
\usepackage{layout}

\begin{document}

\layout

\end{document}

Using the geometry package, you can easily change these settings.

Answer 2

It is better to use geometry package. Put it in his preamble.

\usepackage[a4paper,twoside,inner=0pt,outer=0pt]{geometry}

or

\usepackage[letterpaper,twoside,inner=0pt,outer=0pt]{geometry}