How to modify the space between the numbers and text of sectioning titles in the table of contents?

Question

I'm preparing a document using the book class. In the table of contents, the space between the subsection number and title is too wide. How to reduce it?

Answer 1

Without any packages:

In the standard documentclass without the influence of a package like titletoc you have to redefine the command \l@subsection. In the file book.cls you find the following settings:

\newcommand*\l@section{\@dottedtocline{1}{1.5em}{2.3em}}
\newcommand*\l@subsection{\@dottedtocline{2}{3.8em}{3.2em}}
\newcommand*\l@subsubsection{\@dottedtocline{3}{7.0em}{4.1em}}
\newcommand*\l@paragraph{\@dottedtocline{4}{10em}{5em}}
\newcommand*\l@subparagraph{\@dottedtocline{5}{12em}{6em}}

The command \@dottedtocline expects the following parameters:

\renewcommand{\l@<typ>}{\@dottedtocline{<level>}%
                                       {<indentation>}%
                                       {<numwidth>}}

To reduce the indentation of subsection you can do:

\makeatletter
 \renewcommand*\l@subsection{\@dottedtocline{2}{1.8em}{3.2em}}
\makeatother

Example:

\documentclass{book}
\makeatletter
\renewcommand*\l@subsection{\@dottedtocline{2}{1.8em}{3.2 em}}
\makeatother
\begin{document}
\tableofcontents
\chapter{foo}
\section{bar}
\subsection{foobar}
\end{document}

The method is equal for floating environments. The standard class book.cls provides \l@figure and and \l@table with the following settings:

\newcommand*\l@figure{\@dottedtocline{1}{1.5em}{2.3em}}
\let\l@table\l@figure

---

Package titletoc

By using the package titletoc you can set the indentation using \dottedcontents:

\dottedcontents{<section>}[<left>]{<above-code>}
{<label width>}{<leader width>}

Example

\documentclass{book}
\usepackage{titletoc}
\dottedcontents{subsection}[5.5em]{}{3.2em}{1pc}

\begin{document}
\tableofcontents
\chapter{foo}
\section{bar}
\subsection{foobar}
\end{document}

The argument <section> can be somewhat irritating. The argument allows the name without a leading backslash so that figure and table are allowed, too.

---

Package tocloft

The package tocloft offers more than the following setting. The indentation is set by the length \cftXindent. The X stands for:

• part for \part titles
• chap for \chapter titles
• sec for \section titles
• subsec for \subsection titles
• subsubsec for \subsubsection titles
• para for \paragraph titles
• fig for figure \caption title
• tab for table \caption titles

Example:

\documentclass{book}
\usepackage{tocloft}
\setlength{\cftsubsecindent}{2em}

\begin{document}

\tableofcontents
\chapter{foo}
\section{bar}
\subsection{foobar}
\end{document}

---

KOMA-Script

With a recent version of KOMA-Script one can use \RedeclareSectionCommand to change the entries in the table of contents as well. You can use that for all defined sectioning commands.

\documentclass{scrbook}
\RedeclareSectionCommand[%
tocindent=9em,tocnumwidth=7em,]{subsection}
\begin{document}

\tableofcontents
\chapter{foo}
\section{bar}
\subsection{foobar}
\end{document}

The modification of figure and table is equal to the standard class and defined as follow:

\newcommand*\l@figure{\@dottedtocline{1}{1.5em}{2.3em}}
\let\l@table\l@figure

---

Package tocstyle (link in German)

With recent versions of KOMA-Scrpt, many parts of tocstyle are unneeded. It will be completely incorporated in KOMA-Script in the future.

To manipulate the toc (or other list of ...) in combination with a class of the KOMA bundle you should use the package tocstyle. The package is part of the KOMA bundle but with a separate documentation. The influence of the indentation is given indirectly by entryhook which can be set by \settocfeature

One of the benefits oftocstyle is the automatic calculation of the needed indentation.

Example:

\documentclass{scrbook}

\usepackage{tocstyle}
\usetocstyle{KOMAlike}
\settocfeature[toc][2]{entryhook}{\protect\hspace*{-1.5em}\nobreakspace}
\begin{document}

\tableofcontents
\chapter{foo}
\section{bar}
\subsection{foobar}
\end{document}

Answer 2

The macro in charge of setting the numbers and space between the titles is \numberline. It's defined in the LaTeX kernel as:

\def\numberline#1{\hb@xt@\@tempdima{#1\hfil}}

\numberline{<stuff>} sets its argument <stuff> inside a box of width \@tempdima. The length \@tempdima is set by the macros \l@<type> that is responsible for setting any <type> within the ToC (like section, subsection, figure, etc.).

If you wish to have a natural separation between the numbers and titles within the ToC, you need to modify \numberline to not set its contents in a box, but rather just set the number followed by some space, as in:

\renewcommand{\numberline}[1]{#1~}

The above redefinition will set the number followed by a ~ (tie). You can change this to suit your needs (\hspace{<len>}, :~, ...). Note that this will hold for for all elements that use it (including figures in the LoF and tables in the LoT).

\documentclass{article}

\renewcommand{\numberline}[1]{#1~}

\usepackage{lipsum}% Just for this example
\AtBeginDocument{\sloppy}% Just for this example

\begin{document}

\tableofcontents

\section{A section}
\lipsum[1-50]

\setcounter{section}{9}
\section{Another section}
\lipsum[1-50]

\setcounter{section}{99}
\section{Yet another section}
\lipsum[1-50]

\setcounter{section}{999}
\section{Last section}
\lipsum[1-50]

\end{document}

If you're using tocloft, a similar setup applies with some minor alterations, since tocloft allows for the insertion of content before and after the sectional unit numbering:

\usepackage{tocloft}
\makeatletter
\renewcommand{\numberline}[1]{{\@cftbsnum #1\@cftasnum~}\@cftasnumb}
\makeatother