For the sake of variety, a LuaLaTeX-based solution. 

Two remarks about this solution: 

 - The default precision displayed by `\myPerCent` is 3 significant digits. This can be overridden by specifying an optional argument, enclosed in square brackets. 

 - The two mandatory arguments of `\myPerCent` don't have to be numbers. All that's required is that they *evaluate* to numbers using standard math syntax rules.

[![enter image description here][1]][1]

    % !TEX TS-program = lualatex
    \documentclass{article}
    \usepackage{luacode} % for '\luaexec' macro
    \newcommand{\myPerCent}[3][3]{\luaexec{%
       tex.sprint( 100 * string.format("\%.#1g",(#2)/(#3)) )
       }\,\%}
       
    \begin{document}
    \myPerCent{2441}{8667}, \myPerCent[5]{2441}{8667}.
    
    \myPerCent{10/2}{2*3},  \myPerCent[5]{10/2}{2*3}.
    \end{document}


  [1]: https://i.sstatic.net/Z4N4Yrxm.png