How to Change the Font in LaTeX (Family, Size and Custom Fonts)

LaTeX’s default font is Computer Modern. Which way you change it depends on your compiler: font packages for pdfLaTeX, or any installed font through fontspec with XeLaTeX or LuaLaTeX.

What you’ll learn

• Change the font size
• Switch the whole document to sans-serif or monospace
• Pick a font package for pdfLaTeX
• Use any installed font with fontspec
• Style headings and individual words

Change the font size

Use this when you want bigger or smaller text for the whole document or one passage.

Set the base size with a class option. The standard classes (article, report, book) accept 10pt (default), 11pt and 12pt:

\documentclass[12pt]{article}

Change the size locally with a size command inside braces:

\documentclass[12pt]{article}
\begin{document}
This is the default text size.

{\large This is large text.}

{\small This is small text.}

{\footnotesize This is footnote-sized text.}
\end{document}

Size commands are declarations: they affect everything after them until the closing brace. Their actual size depends on the base size:

For an exact size, use \fontsize{size}{baselineskip}\selectfont, for example {\fontsize{14}{17}\selectfont Text}. For a 14pt body, use \documentclass[14pt]{extarticle} from the extsizes package.

Change the font family

Use this when the whole document, or a passage, should be serif, sans-serif or monospace.

LaTeX has three families: roman (serif, the default), sans-serif and typewriter (monospace). To change the default family for the whole document, redefine \familydefault in the preamble:

% Whole document in sans-serif
\renewcommand{\familydefault}{\sfdefault}

% Whole document in monospace
\renewcommand{\familydefault}{\ttdefault}

Warning: \documentclass[sans]{article} is not a valid option. LaTeX ignores it and logs Unused global option(s): [sans], so the document stays serif.

For a few words, use the text commands:

• Serif: \textrm{...}
• Sans-serif: \textsf{...}
• Monospace: \texttt{...}

\documentclass{article}
\usepackage{courier} % changes only the monospace (\texttt) font
\begin{document}
This is the default serif text.

\textsf{This is sans-serif text.}

\texttt{This is monospace text.}

This is regular text, but here is some code: \texttt{int x = 0;}
\end{document}

Result: body text stays serif, \textsf gives sans-serif, and \texttt uses Courier. The courier package changes only the monospace family. For code listings, see monospace fonts for code listings.

Change the font with a package (pdfLaTeX)

Use this when you compile with pdfLaTeX, the default on Overleaf, and want a different typeface for the whole document.

Load the package in the preamble, together with \usepackage[T1]{fontenc} for proper accented characters and hyphenation:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{newtxtext,newtxmath} % Times-style text and maths
\begin{document}
Times-style text and maths: $\int_0^1 x^2\,dx = \frac{1}{3}$.
\end{document}

The old times package is obsolete: it changes the text but leaves the maths in Computer Modern. Use newtx or mathptmx instead.

To combine a Times-style body with Helvetica and Courier:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{mathptmx}             % Times-style text and maths
\usepackage[scaled=0.92]{helvet}  % Helvetica-style sans, scaled to match
\usepackage{courier}              % Courier-style monospace
\begin{document}
This is in Times New Roman, which is the default font for this document.

This part remains in Times, but \textsf{this part is in Helvetica}.

Here is some code in Courier: \texttt{int main() \{ return 0; \}}.
\end{document}

Overleaf’s guide to font sizes, families and styles covers more packages.

Use any font with fontspec (XeLaTeX and LuaLaTeX)

Use this when you need a specific font, such as a university’s required typeface or a system font.

fontspec loads OpenType and TrueType fonts by name. It only works with XeLaTeX or LuaLaTeX; on Overleaf, switch the compiler through the gear icon or the File menu, then Compiler.

\documentclass{article}
\usepackage{fontspec}
\setmainfont{TeX Gyre Termes}   % Times-like serif
\setsansfont{TeX Gyre Heros}    % Helvetica-like sans
\setmonofont{TeX Gyre Cursor}   % Courier-like monospace
\begin{document}
Main text in TeX Gyre Termes, \textsf{sans text in TeX Gyre Heros}
and \texttt{code in TeX Gyre Cursor}.
\end{document}

Result: a document set in fonts that ship with TeX Live. It compiles on Overleaf, and locally with LuaLaTeX; see the common errors below if XeLaTeX can’t find them.

On your own computer, you can name any installed font. This example uses fonts that come with macOS:

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Arial}
\setsansfont{Helvetica}
\setmonofont{Courier New}
\begin{document}
This is in Arial, which is the default font for this document.

This text is in Arial, but \textsf{this part is in Helvetica}.

Here is some code in Courier: \texttt{int main() \{ return 0; \}}.
\end{document}

• Helvetica isn’t installed on Windows or available on Overleaf; use TeX Gyre Heros or Arial there.
• Overleaf has a long list of fonts you can name directly, including Arial, Times New Roman and Courier New. See which fonts Overleaf supports with fontspec.
• Font features go in the preamble: \setmainfont{TeX Gyre Pagella}[Numbers=OldStyle] gives old-style figures.

Change the font of headings

Use this when headings should look different from the body text.

The titlesec package controls section heading fonts:

\usepackage{titlesec}
\titleformat{\section}{\Large\bfseries\sffamily}{\thesection}{1em}{}

• \section is the heading level to change; repeat for \subsection and others.
• \Large\bfseries\sffamily sets size, weight and family.
• \thesection prints the number, and 1em is the gap before the title.

Bold, italic, small caps and other styles

Use these commands for individual words:

Load ulem as \usepackage[normalem]{ulem}. Without [normalem], it redefines \emph to underline instead of italicise:

Which method should you use?

Common errors

• Fatal Package fontspec Error: The fontspec package requires either XeTeX or LuaTeX: you’re compiling with pdfLaTeX. Switch to XeLaTeX or LuaLaTeX, or use a font package.
• The font "…" cannot be found: the font isn’t installed on that system. On a local XeLaTeX install, fonts that come with TeX Live may not be found by name; compile with LuaLaTeX or install the font in your system.
• Unused global option(s): [sans]: sans isn’t a class option. Use \renewcommand{\familydefault}{\sfdefault}.
• \emph text is underlined: load ulem with [normalem].
• Class option 14pt ignored: use extarticle or another class that supports it.

If you’re moving the document to Word afterwards, see fonts after converting LaTeX to Word, where a reference document sets the Word fonts. For long formulas in your new font, see line breaks in LaTeX equations. More formatting guides are in the LaTeX guides.