# how to change the chapter font size?

How can i change the following code to make the chapter title font size bigger?

\titleformat{\chapter}[block]
{\normalfont\sffamily}{}{0pt}
{\parbox[b]{\chapnumb}{%
\fontsize{120}{110}\selectfont\thechapter}%
\parbox[b]{\dimexpr\textwidth-\chapnumb\relax}{%
\raggedleft%
\hfill{\LARGE#1}\\
\rule{\dimexpr\textwidth-\chapnumb\relax}{0.4pt}}}


The above code reproduce this:

and i would like to be like this:

Code is taken from the following post: Chapter style like this without memoir?

• Hi and welcome. Your question, aas it stands now, is a bit unclear. Can you give us some more information, probably even showing us a minimal working example (MWE) (including the documentclass) and what you want? – Johannes_B Oct 18 '14 at 19:07
• Change \LARGE to whatever you need. – Andrew Swann Oct 18 '14 at 19:09
• Thank you for the welcoming! I edit my question to be more clear. – Mpizos Dimitris Oct 18 '14 at 19:19

The use of the [explicit] option to titlesec forces the user to input #1 for the title format. You'll note a reference to \LARGE#1 within the definition of \titleformat for \chapter (both). Adjust this to suit your needs.

Below I've updated the font reference so you can (re)define \chaptertitlefont:

\documentclass{book}
\usepackage[explicit]{titlesec}
\usepackage{lmodern,lipsum}

\newlength\chapnumb
\setlength\chapnumb{4cm}
\newcommand{\chaptertitlefont}{\normalfont\sffamily\Huge}

\titleformat{\chapter}[block]
{\normalfont\sffamily}{}{0pt}
{\parbox[b]{\chapnumb}{%
\fontsize{120}{110}\selectfont\thechapter}%
\parbox[b]{\dimexpr\textwidth-\chapnumb\relax}{%
\raggedleft%
\hfill{\chaptertitlefont#1}\\
\rule{\dimexpr\textwidth-\chapnumb\relax}{0.4pt}}}
\titleformat{name=\chapter,numberless}[block]
{\normalfont\sffamily}{}{0pt}
{\parbox[b]{\chapnumb}{%
\mbox{}}%
\parbox[b]{\dimexpr\textwidth-\chapnumb\relax}{%
\raggedleft%
\hfill{\chaptertitlefont#1}\\
\rule{\dimexpr\textwidth-\chapnumb\relax}{0.4pt}}}

\begin{document}

\chapter*{A Long Title for an Unnumbered Test Chapter}
\lipsum[4]
\chapter{Introduction}
\lipsum[4]

\end{document}


The above changes the font to \Huge. If you want larger font sizes, see Fonts larger than \Huge?

• thanks for the anwer.The code u provide outputs an error.I guess its because i have to define the title font.My question is how can i do that? – Mpizos Dimitris Oct 18 '14 at 19:36
• @MpizosDimitris: So when you copy-and-paste-and-compile the code above, it outputs an error? What is the error? Do you have all the packages installed? – Werner Oct 18 '14 at 20:08
• ! Undefined control sequence.<argument> ...gedleft \hfill {\chaptertitleformatIntroduction}\\ \rule {\di... \chapter{Introduction} and C:\Users\Administrator\Desktop\Thesis\latex\Appendices/AppendixA.tex .I think i have the puckages needed installed as the code that I post is running normally. Or maybe i need an additional package regarding ur code? – Mpizos Dimitris Oct 18 '14 at 20:11
• @MpizosDimitris: I've corrected the example code... – Werner Oct 18 '14 at 20:23

A slighly simpler version, using the specific commands defined in the titlesec package (\titlerule, filleft and the like), plus some colour.

\documentclass[12pt, a4paper]{book}% http://ctan.org/pkg/amsproc

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\usepackage[x11names]{xcolor}
\usepackage[explicit]{titlesec}%
\newlength\rulew
\titleformat{\chapter}[block]
{\filleft\sffamily\bfseries}
{\fontsize{120}{120}\selectfont\textcolor{LightSteelBlue3!80!}{\thechapter}\hskip8mm\titlerule[0.8pt]}
{0em}
{\fontsize{32}{36}\bfseries\llap{\parbox[b]{0.7\linewidth}{\filleft#1\vskip0.6ex}}}%
\titlespacing*{\chapter}{0pt}{-45pt}{18ex}

\usepackage{lipsum}

\begin{document}

\chapter{A Chapter Title\\with a Subtitle}

\lipsum[2]

\end{document}