how to get the page layout in mm?

Question

I try to understand the actual page layout - but like to have it in mm units. I use layouts but get the sizes in pt. There is a command \printinunitsof{mm} but I do not understand how to use it. In my example code, it does not have an effect. Where does it belong?

\documentclass[msmallroyalvopaper
    ]{memoir}

\usepackage{layouts}

\begin{document}

\printinunitsof{mm}
\begin{figure}
    \currentpage
    \oddpagelayouttrue
    \pagedesign
    \caption{Odd page layout for this document} \label{fig:ptrs}
\end{figure}

\include{intro}

\end{document}