KCalc is part of the kdeutils package within the KDE project and will normally be provided as part of a KDE installation. For more details about KDE visit http://www.kde.org.
If you wish to compile KCalc by itself, source code can be found at ftp://ftp.kde.org/pub/kde/, the main FTP site of the KDE project.
Compile and install with the usual:
% ./configure % make % make install |