First, select the shape of your shade. There are many different styles so try and picture how each one would look on your lamp and in your room.
Second, select the shades bottom diameter. The best way to determine the bottom diameter of the shade for your table lamp is to measure the lamp height from the bottom edge of the table lamp base to the top of the lamp stem, (just below the socket cap).
The shade you choose for your lamp should have a bottom diameter that is within 2”, plus or minus, the measured height of your lamp. For example if your lamp height is 14" tall, your shade should have a bottom diameter of 12"-16"
Third, select the shades overall height. The overall height of the shade is directly related to the height of the harp. As a general rule, the overall height of the shade should not exceed the the height of the harp plus 1/ 2”, and should not be smaller than the height of the harp minus 1/ 2”.
For example, if your harp is 7” tall, the shade you select should have an overall height in the range of 6 1/ 2” to 7 1/ 2”. The shade height is important because you want adequate coverage of the bulb without covering the lamp base.
Hopefully this helps and it makes your shade decision making easier. Don't forget to visit Interiormall.com for an extensive array of lamp shades.