Use textcommand only for text, numbercommand only for number, command for both; you can see some examples in section Variations in titles .
Thanks for the reply. The problem with separating the text and number is that the space separating the text and number still appears in the chapter text. On a similar note, why doesn't 'show makeup' display the right margin number? \def\MyChapterNumberText#1{ \inright{\begingroup \midaligned{#1} \endgroup} } \def\MyChapterText#1{ \begingroup \leftaligned{#1} \endgroup } \setuphead [Topic, chapter] [numbercommand=\MyChapterNumberText, textcommand=\MyChapterText, numberstyle={\switchtobodyfont[48pt]}, textstyle={\switchtobodyfont[12pt]}, color=black, number=yes, page=right, continue=no, header=empty, before=\vbox to 3cm\bgroup, after=\vss\egroup] \starttext %\showmakeup \chapter{This is a Chapter Title} \input tufte \section{This is a section title} \input tufte \par \input knuth \par \subsection{This is a sub-section title} \input tufte \par \input knuth \par \stoptext