Measuring Glass Shades & Fitters
How are glass shades measured?
There are three important dimensions for glass shades: fitter size, height and width. The fitter is the outer diameter of the lip which is inserted into the fixture's shade holder. This will measure a little less than the fitter size so it can fit into the shade holder of the same measurement. The height of a glass shade is taken from the base of the fitter lip to the bottom of the shade. The width is measured across the widest portion of the shade, which may be the top, middle or bottom, depending on the shade type.