# Superscript/subscript fonts different from body font

The following minimal example:

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}

\begin{document}
10$^5$ and CO$_2$.
\end{document}


produces the following:

The superscript and subscript fonts are different from the body font. Why is this happening, and how can I ensure that those fonts are the same as the body font?

• Those are the fonts used in math mode. There are packages like siunitx or chemformula that can help you with a consistent appearance. – Johannes_B May 22 '15 at 11:33

In my view, it's abusing the math environment to use it only to make superscript and subscript numbers in a context that is not math. So I would use \textsuperscript and \textsubscript instead.

\documentclass{article}
\usepackage{fixltx2e}
\renewcommand{\familydefault}{\sfdefault}

\begin{document}
10\textsuperscript{5} and CO\textsubscript{2}.
\end{document}


• I agree completely with your first sentence, but 10^5 is maths, and should (if not using siunitx's \num -- which I wouldn't here) be written as $10^5$. In this case $\mathsf{10^5}$ is appropriate. – Chris H May 22 '15 at 15:01
• Note that fixltx2e is an obsolete package. Use changes. – Fran May 23 '15 at 4:33
• @ChrisH I don't fully agree with that. 10^5 is in of itself not math - I consider it to be just a number. The context should decide. To me, a sentence like "There are 10^5 CO_2 particles in this sample" is no more math than a sentence "I am 20 years old". They're both just numbers in a sentence telling us the amount of particles and years. If the number is part of a mathematical operation, then that's another story: $10^5 - 1 = 99999$ is math just like $20 - 1 = 19$ is. – Sverre May 23 '15 at 12:25
• @Fran, true but it's made obsolete so recently that I think most users probably need it here. I'll wait until after the release of texlive2015 to consider it obsolete. – Sverre May 23 '15 at 12:26

Those are the fonts used in math mode. Using mathsf you can switch to a sans serif math font. On the other hand, there are packages like siunitx and chemformula that ease the input significantly.

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}
\usepackage{siunitx}
\usepackage{chemformula}
\begin{document}
10$^5$ and CO$_2$.\par
10$^\mathsf{5}$ and CO$_\mathsf{2}$.\par
\num{1e5} and \ch{CO2}.\par
\end{document}

• With siunitx, \num{e5} works if you don't want the 1x part. – TonioElGringo May 22 '15 at 11:43
• @TonioElGringo Yeah, but the syntax is very powerful and should be shown ;-) – Johannes_B May 22 '15 at 11:54

A variant with package siunitx for numbers and units (with font detection) and mhchem for chemical formulas:

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}
\usepackage[version=3]{mhchem}
\usepackage{siunitx}
\begin{document}
\num{e5} and \ce{CO2}.
\end{document}


Use sfmath package here.

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}
\usepackage{sfmath}
\begin{document}
10$^5$ and CO$_2$.
\end{document}