How to measure a lamp
Step #1
Lamp Step1
Hold the measuring tape across the bottom diameter. Once you’ve recorded the measurement for the top diameter, place the tape measure at one end of the bottom edge of the lamp shade. Pull it across to the opposite side to get the proper measurement.
Step #2
Lamp Step2
Record the number. Write down the second measurement with the top diameter to make sure you know the precise size of the shade. Mark this measurement as “bottom diameter.”
Step #3
Lamp Step3
Measure the shade’s sloping side. Set the shade down on the table once more. Place the end of the measuring tape at the top edge of the shade, and pull it down to the bottom edge to measure the slope.
  • Sometimes a shade’s slope is referred to as its height.
  • If you have a square lamp shade, it obviously won’t have a slope. Measure from top to bottom in the same manner, though, to get the height of the shade.
Step #4
Lamp Step4
Jot down the number. Record the next measurement with the top and bottom diameters. Mark it as the shade’s “slope” or “side.”
Step #5
Lamp Step5
Use the measurements as a guide for a replacement shade. Once you’ve recorded all 3 measurements for the shade, you can choose the proper size for a new shade. Most shades list the measurements in the following order: top diameter, bottom diameter, and slope/height.