\documentclass{report}
\usepackage{gcheck}

\usepackage[dvips,showframe]{geometry}
\geometry{screen,margin={50pt,30pt},foot=20pt}

\begin{document}

\typeout{}
\dcheck\paperwidth{640.187pt}
\dcheck\paperheight{512.1496pt}
\dcheck\textwidth{540.187pt}
\dcheck\textheight{452.1496pt}
\dcheck\oddsidemargin{-22.26999pt}
\dcheck\evensidemargin{-22.26999pt}
\dcheck\topmargin{-79.26999pt}
\dcheck\headheight{12pt}
\dcheck\headsep{25pt}
\dcheck\footskip{20pt}
\dcheck\marginparwidth{65pt}
\dcheck\marginparsep{11pt}
\dcheck\columnsep{10pt}
\dcheck\hoffset{0pt}
\dcheck\voffset{0pt}
\ccheck\mag{1000}
\checkresults
\typeout{}

\manyfoxes\manyfoxes\manyfoxes\manyfoxes
\manyfoxes\manyfoxes\manyfoxes\manyfoxes
\end{document}
