\documentclass[a4paper,12pt,french]{article}
\usepackage[top=0.9in, bottom=0.8in, left=0.7in, right=0.7in]{geometry}


\usepackage{tikz}
\usetikzlibrary{calc}
\usepackage{calc}
\usepackage{fontawesome5}
\newlength{\tmptotalheightcurrenttxt}
\setlength{\tmptotalheightcurrenttxt}{1em}
\newlength{\tmptotaldepthcurrenttxt}
\setlength{\tmptotaldepthcurrenttxt}{0.1em}

\begin{document}

\NewDocumentCommand\nocalc{ O{black} }{%
	\settototalheight{\tmptotalheightcurrenttxt}{\hbox{azertyuiopqsdfghjklmwxcvbnAZERTYUIOPQSDFGHJKLMWXCVBN}}%
	\settodepth{\tmptotaldepthcurrenttxt}{\hbox{azertyuiopqsdfghjklmwxcvbnAZERTYUIOPQSDFGHJKLMWXCVBN}}%
	\hspace*{-0.1\tmptotalheightcurrenttxt}%
	\raisebox{-\tmptotaldepthcurrenttxt}{%
		{\begin{tikzpicture}[line width={0.1\tmptotalheightcurrenttxt}]
			\node[#1,inner sep=0pt,scale=0.8] (TMPPP) at (0,0) {\faCalculator} ;
			\draw[#1,line cap=round] (TMPPP.north east)--(TMPPP.south west) ;
		\end{tikzpicture}}%
    }%
    \hspace*{-0.1\tmptotalheightcurrenttxt}%
}

En ligne \nocalc\ avec un petit texte

\textcolor{blue}{\sffamily\LARGE En ligne \nocalc[blue] avec un petit texte}

\textcolor{red}{\ttfamily\Huge En ligne \nocalc[red] avec un petit texte}

\scalebox{4}[4]{Avec une échelle \nocalc\ perso}

\end{document}