You have the perfect lamp, and now you need to find a suitable lamp shade. Here, we show you how to measure lamp shades in a few simple steps to help you get just the right size.

How to Measure Lamp Shades

Most shades are sized according to the top, bottom, and slant measurements:

Top denotes the size across the top of the shade – diameter for round shades, diagonal width for square or rectangular shades. The top dimension is a factor in the overall shape of the lamp shade, but it does not contribute directly to how the shade will fit the lamp.

Bottom denotes the diameter or width of the bottom of the shade. This bottom measurement designates the ‘size’ of the lamp shade. A 30cm lamp shade, for example, is one that measures 30cm across the bottom.

Slant, which is sometimes referred to as ‘slope’ or ‘side,’ is the length of the side of the lamp shade.

Measuring to Replace an Existing Shade

If you are replacing an existing shade, you're already well on your way. Start by removing the lamp shade from the lamp to make it easier to measure.

Top: For a round lamp shade, place a measuring tape across the top of and as close to the center as possible. For a square or rectangular lamp shade, measure from corner to corner for the top.

Bottom: Flip the lamp shade upside-down and measure the bottom of the lamp shade the way you measured the top.

Slant: Flip the lamp shade back over and measure from the top edge to the bottom edge, keeping the measuring tape flat against the shade.

Measuring for a New Shade

If you don't have an existing lamp shade to measure, then you can determine the best size by following a few basic design guidelines:

• The dimensions of the lamp shade should complement the lamp – not too big, not too small. The top measurement of the lamp shade should be at least as wide as the base of the lamp, while the bottom measurement should be wider than the widest part of the base. However, the bottom should not exceed the height of the lamp (i.e., the distance from the bottom of the lamp to its socket).
• The height of the lamp shade depends on the type of lamp. A table lamp looks best with a shade that, when measuring from the bulb socket to the base, is about two-thirds the height of the lamp. For a floor lamp, look for a shade that is approximately one-third the height of the lamp.
• The lamp shade should be large enough to hide any non-decorative components. The bottom of the lamp shade should come to the top of the body of the lamp. This ensures that mechanical parts are hidden – only a bit of the neck should show. The lightbulb should never stick out at the top of the lamp shade.