TextFrame.AutoSize (PowerPoint)

Returns or sets a value that indicates whether the size of the specified shape is changed automatically to fit text within its boundaries.

Possible Values are ppAutoSizeMixed - Mixed size, ppAutoSizeNone - Does not change size, ppAutoSizeShapeToFitText - Auto sizes the shape to fit the text.

The value of the AutoSize property can be one of these PpAutoSize constants.

ActivePresentation.Slides(1).Shapes(1).TextFrame.AutoSize = ppAutoSizeMixed