When you buy a shade for a new lamp or for a lamp that you already have you need to make sure to choose the right size. You can use a tape measure to determine the bottom and top diameters and also the vertical height. These few measurements will help you to make the right decision and not end up with a lamp shade that is too large or too wide. All tops and bottoms are measured by their diameters. Round lamp shades are measured top, bottom and side. (T x B x S)
Squares, rectangles and ovals are all measured: Top, bottom and slant/height. (A x B) x (C x D) x E .
Now you are ready to choose the right size of Shade for you lamp!