You'd better devise your UI in the Designer: this way you save yourself most of troubles with positioning and sizing widgets. Both the console and the trackingWidget are descendant of some standard parts of Qt: for example,the console is derived from QTextEdit most likely. Thus, create a main window in the Designer, add a QTextEdit, add a widget, which is the base of trackingWidget, set sizes, and put both in a horizontal layout. Set spacing of the layout and promote your widgets to console and the trackingWidget (all of this is made in the Designer). Save. Getting your UI to the screen is a matter of two simple calls: setupUi() and show().