\documentclass[paper=a4]{article} \usepackage{geometry} \usepackage{dejavu-otf} \usepackage[space=~]{isopt} \makeatletter \let\FV\ISOpt@fileversion \makeatother \usepackage{biblatex} \addbibresource{\jobname.bib} \title{Writing a \TeX\ length in ISO style\thanks{Thanks to Heiko Oberdiek}\\[7pt] \normalsize v. \FV} \author{Herbert Voß} \begin{document} \maketitle \section{How it works} By default \TeX\ writes an internal length in the following way: \verb|\the\baselineskip|$\rightarrow$\the\baselineskip There is no space between value and unit. Package \texttt{isopt} provides the macro \texttt{\textbackslash ISO} which needs a \TeX\ length as argument and prints it with the default \verb|\thinspace| \verb|\ISO\the\baselineskip|$\rightarrow$\ISO\the\baselineskip \begin{verbatim} \sbox0{Hello World} The box is \ISO\wd0\ wide, \ISO\ht0\ high and has a depth of \ISO\dp0. \end{verbatim} \sbox0{Hello World} The box is \ISO\wd0\ wide, \ISO\ht0\ high and has a depth of \ISO\dp0. There is also a short form \verb|\THE| which is defined as \verb|\ISO\the|. It saves only some keystrokes: \verb|\THE\tabcolsep|$\rightarrow$\THE\tabcolsep If you prefer the tilde \verb|~| as space between value and unit, then pass it as optional argument of the package: \begin{verbatim} \usepackage[space=~]{isopt} \end{verbatim} The predefined space is \verb|\usepackage[space=\thinspace]{isopt}| \section{Limitations} The current version does not support a rubber length like \verb|\the\parskip|$\rightarrow$\the\parskip \nocite{*} \printbibliography \end{document}