How can I print “page # of ##” with the total page number in KOMA (scrlttr2)?

Question

This questions explains how you can show the total page number of your document in the footer on each page, i.e. show a “page # of ##” instead of the default “page # of #”.

However, even though someone asked for that in the comments, it does not explain how to do that in a KOMA class. It has been suggested to ask a new question.

I use scrlttr2 for a letter, so I'd like to do the same. So how can I do it there?

Answer 1

You can simple (without additional packages) redefine \pagemark to your needs:

\renewcommand*\pagemark{%
  \usekomafont{pagenumber}{\pagename~\thepage~of~\letterlastpage}%
}

Example:

\documentclass{scrlttr2}
\usepackage{blindtext}% only for dummy text

\renewcommand*\pagemark{%
  \usekomafont{pagenumber}{\pagename~\thepage~of~\letterlastpage}%
}

\begin{document}
\begin{letter}{Foo}
\opening{Hello,}
\Blindtext[10]
\end{letter}

\begin{letter}{Bar}
\opening{Hello,}
\Blindtext[15]
\end{letter}

\end{document}

Answer 2

The scrlttr2 class offers specific commands for modifying headers and footers, through the scrlayer-scrpage package. The mwe below is a starting point. Note that there is no need to use the lastpage package, as the class provides the internal \lastletterpage counter.

\documentclass{scrlttr2}
\usepackage{scrlayer-scrpage}

\cefoot{Page \thepage\ of \letterlastpage}
\cofoot{Page \thepage\ of \letterlastpage}

\usepackage{lipsum}
\begin{document}
\begin{letter}{%
    Jerry Garcia\\
    710 Ashbury St\\
    San Francisco\\
    CA 94117
    }
    \opening{Dear Friend,}
    
  \lipsum\lipsum    

\end{letter}

\begin{letter}{%
    Jerry Garcia\\
    710 Ashbury St\\
    San Francisco\\
    CA 94117
    }
    \opening{Dear Friend,}

  \lipsum\lipsum    

\end{letter}

\end{document}