memoir: Roman chapters in ToC

Question

When I set

\renewcommand{\thechapter}{\Roman{chapter}}

I can't figure out how to increase the space in the toc between 'VIII'/'XIII'/'XIV' and the section title. (shorter Roman numbers fit nicely.) I need at least another 1ex, or possibly 1em, more space for the chapter number in the toc. (Maybe the default should be just a little spacier??)

I read chapter 9 of the memoir manual a few times, but

\makeatletter
\renewcommand{\@pnumwidth}{20em}
\makeatother

did not work. What is the right way to fix this?

Answer 1

memoir implements a similar setup to what is provided by tocloft natively. So, you need to adjust the lengths \cftchapternumwidth (and lower levels, possibly, like \cftsectionnumwidth) to give the Roman numerals a little more space in the ToC.

\documentclass{memoir}
\usepackage{lipsum}
\renewcommand{\thechapter}{\Roman{chapter}}
\setlength{\cftchapternumwidth}{3em}
\begin{document}
\tableofcontents
\sloppy% Just for this example
\chapter{First chapter}\lipsum[1-50]
\chapter{Second chapter}\lipsum[1-50]
\chapter{Third chapter}\lipsum[1-50]
\chapter{Fourth chapter}\lipsum[1-50]
\chapter{Fifth chapter}\lipsum[1-50]
\chapter{Sixth chapter}\lipsum[1-50]
\chapter{Seventh chapter}\lipsum[1-50]
\chapter{Eighth chapter}\lipsum[1-50]
\chapter{Ninth chapter}\lipsum[1-50]
\chapter{Tenth chapter}\lipsum[1-50]
\chapter{Eleventh chapter}\lipsum[1-50]
\chapter{Twelfth chapter}\lipsum[1-50]
\chapter{Thirteenth chapter}\lipsum[1-50]
\chapter{Fourteenth chapter}\lipsum[1-50]
\end{document}