How to make the integral sign smaller?

Question

Is it possible to make the integral sign smaller? I found that in the Display Mode the integral sign seems automatically longer. But I am in a context where smaller integral sign would be preferred.

Thanks.

Answer 1

The nccmath package provides a medium-size integral sign , with the \medint\int command. There are also medium-sized fractions (\mfrac), the more general medmath{...} command. and medsize environments. You obtain formulæ with a size of ~80 % \displaystyle, avoiding the discrepancy with \textstyle .

The following code provides a demo:

\documentclass{article}
\usepackage[utf8]{inputenc}%
\usepackage{mathtools, nccmath}
\usepackage{array} 
\newcommand{\Leg}[3][]{\left(\frac{#2}{#3}\right)_{#1}}

\begin{document}

Different kinds of integrals: 

    \begin{align*} 
    \int_{0}^{1}\frac{\mathrm d x}{1 + x^2} & = \frac\pi 4 %
     &\texttt{\textbackslash medint: \quad} \medint\int_{0}^{1}\frac{\mathrm d x}{1 + x^2} & = \frac\pi 4 \\[2ex]
    \begin{tabular}{ >{\ttfamily}r}
    \textbackslash medint\\ +\textbackslash mfrac\enspace\end{tabular} \quad \medint\int_{0}^{1}\mfrac{\mathrm d x}{1 + x^2} & = \mfrac\pi 4
       & \texttt{\textbackslash textstyle: }\quad\textstyle{\int_{0}^{1}}\frac{\mathrm d x}{1 + x^2} & = \frac\pi 4
    \end{align*}%

\end{document}

Answer 2

If you prefer to have any size of the integral sign (you can choose the size that you like), it is possible to use scalerel package with the option \scaleobj{<scale factor>}{...}.

\documentclass[a4paper,12pt]{article}
\usepackage{mathtools}
\usepackage{scalerel}


\begin{document}
\[
\int^{b}_{a}\frac{1}{x}\,dx, \quad 
\scaleobj{.5}{\int^{b}_{a}}\frac{1}{x}\,dx,
\quad 
\scaleobj{1.5}{\int^{b}_{a}}\frac{1}{x}\,dx,
\quad 
\scaleobj{2}{\int^{b}_{a}}\frac{1}{x}\,dx,\quad
\scaleobj{.3}{\int^{b}_{a}}\frac{1}{x}\,dx
\]
\end{document}