How to avoid the geometry package to change to top/bottom margins?

Question

For my master thesis, i need to print recto verso with margins 4cm and 1 cm (left and right). So I use the following package:

\usepackage[inner=4cm,outer=1cm]{geometry}

However, this increases my bottom margin (with about 1 cm i'm guessing) which ruins my entire document. How can I avoid this package to influence the other margins (when i don't even define them explicitly)?

Answer 1

If I run this sample document

\documentclass{book}
\usepackage[a4paper,pass,verbose]{geometry}

\usepackage{lipsum}

\begin{document}
\lipsum
\end{document}

I get, in the log file and on the console, the relevant lengths:

* \textheight=550.0pt
* \topmargin=22.0pt
* \headheight=12.0pt
* \headsep=18.06749pt

Rounding \headsep is irrelevant, so I'll use 18pt:

\documentclass{book}
\usepackage[a4paper,verbose]{geometry}
\geometry{
  inner=4cm,outer=1cm,
  top=\dimexpr1in+22pt+12pt+18pt,% standard offset+topmargin+headheight+headsep
  headheight=12pt,
  headsep=18pt,
  textheight=550pt,
}

\usepackage{lipsum}

\begin{document}
\lipsum
\end{document}

This prints

* \textheight=550.0pt
* \topmargin=22.0pt
* \headheight=12.0pt
* \headsep=18.0pt

which agrees with the standard setup.

With \documentclass[11pt,a4paper]{book} (the twoside and openright options are on by default), the values obtained in the first step are

* \textheight=595.80026pt
* \topmargin=24.0pt
* \headheight=12.0pt
* \headsep=19.8738pt

so the change should be

\documentclass[11pt]{book}
\usepackage[a4paper,verbose]{geometry}
\geometry{
  inner=4cm,outer=1cm,
  top=\dimexpr 1in+24pt+12pt+19.8738pt,% standard offset+topmargin+headheight+headsep
  headheight=12pt,
  headsep=19.8738pt,
  textheight=595.80026pt,
}
\usepackage{lipsum}

\begin{document}
\lipsum
\end{document}

with this setup I get as output

* \textheight=595.80026pt
* \topmargin=24.0pt
* \headheight=12.0pt
* \headsep=19.8738pt

Note that, in any case, LaTeX just looks at the values of \topmargin, \headheight, \headsep and \textheight; the bottom margin is whatever remains.

This is the output I get for the first page with the new settings

and this is the output without loading geometry

Answer 2

From here, you can do it manually

\addtolength{\oddsidemargin}{-.875in}
\addtolength{\evensidemargin}{-.875in}
\addtolength{\textwidth}{1.75in}

\addtolength{\topmargin}{-.875in}
\addtolength{\textheight}{1.75in}}

Note that this has to be added to the preamble.

Answer 3

As far as I know, geometry doesn't allow changing some but not all margins, so you must manually get the right height. The best way get exactly the right height is to set the height, not the margins.

If you put \the\textheight somewhere in your document without using the geometry package it will output the default textheight (for your setup this seems to be 595.80026pt). Then you can use textheight=595.80026pt as an argument to geometry to get the same height of the text, which will allow the same amount of text on each page. Note that

1. The top and bottom margin may still have changed. Set one of them (e.g. bottom=3.1cm) to get the same appearance.
2. If the textwidth changes when you change the margins then this may ruin the whole document anyway. This is harder to fix, but perhaps you can set textwidth the same way and make the margins approximately 1 and 4 cm. Otherwise you can try to change the textheight to at least fit about the same amount of text on each page.