Hi Well to get below the QWTPlot plot would be QWTPlotptr->y() + QWTPlotptr->height() However, a more solid approach could be to use a QLabel as a canvas using a pixmap. That way, its very easy to position even if using layouts to make GUI auto adjust to different screen sizes. void PaintShapes() { // take size of label int h = ui->label->height(); int w = ui->label->width(); // make a pixmap of the wanted size QPixmap pix(w, h); // assign painter to it so we can paint on it QPainter paint(&pix); // fill it pix.fill( Qt::white ); // paint on canvas paint.setPen(QColor(0, 0, 0, 255)); paint.drawRect(0, 0, w, h); ..other paint operations-.. // set the pixmap to the label so its shown. ui->label->setPixmap(pix); }