If the lamp has a clip-on lamp shade fitter, you can simply pull it off the light bulb. Be gentle, though, to avoid damaging the bulb. If the lamp has a spider lamp fitter with a lamp harp, unscrew the finial that holds the shade onto the harp and then lift the shade off. If your lamp has an UNO lamp shade fitter, unscrew the bulb and carefully lift the shade off.
Sometimes, a shade’s slope is referred to as its height. If you have a square lamp shade, it obviously won’t have slope. Measure from top to bottom in the same manner, though, to get the height of the shade.
Place the tape measure across the center of the lamp base from one side to the other just as you did with the shade to get the proper diameter.
