How To Determine A Lamp Shade Size

Stacy Randall
by Stacy Randall

Lamps provide many benefits to a home, both practical and beautiful. They can help create various moods through lighting and make a statement. But if you don’t have the right size lamp shade, it can throw off the look and the light.

A lamp shade should be twice as wide as the broadest part of the base. The height should be ⅓ of the total lamp (including the bulb and the harp). Or you can do ⅔ the height of the lamp base. Therefore, if your lamp is 10 inches wide and a total of 30 inches tall, you need a shade that’s 20 inches wide and 10 to 12 inches tall.

Lamps are one of the best ways to accessorize and add functionality to your home. And you can find a ton of unique designs in antique shops, flea markets, and thrift stores. But many times, purchasing a separate shade can help make your bargain finds more personal. It just comes down to choosing the right lamp shade size.

How Do I Choose The Right Lamp Shade?

If your lamp currently has a shade and you love the size, just not the design, you can simply swap it out with one the same size. But what if you’re trying to find a new shade to go with a recently found treasure? Or, the current lamp shade size isn’t working — then what do you do?

It’s important to measure correctly for your new lamp shade, so it looks good and also provides the right amount of light. An improperly sized lamp shade can block light, show too much light, look awful, or expose ugly lamp hardware.

The two primary dimensions when it comes to choosing the right size lamp shade are height and width. Both of these measurements depend on the height and width of the lamp.

Picking The Perfect Lamp Shade Height

When choosing the best height for a lamp shade, think of the total picture. The overall proportion of lamp shade to lamp base should be 40% to 60%. To achieve this proportion using measurements, first measure your lamp height.

You can measure the lamp’s total height, including the bulb and harp. Or, you can measure the height of the lamp base from the bottom to the socket base.

If basing your shade height off the total lamp, opt for a shade ⅓ the height. Therefore, if the total lamp is 24 inches tall, look for a shade that is 8 inches tall.

However, if you plan to use the lamp base height, the shade should be roughly ⅔ the height of your lamp base. Therefore, if the lamp base is 16 inches tall, try a shade approximately 10 inches tall.

This gives you a range of 8 to 10 inches for your lamp shade height. A table lamp shade height should be between 60% and 80% of the lamp base height. A floor lamp shade should be about 30% to 50% of the lamp height. To determine the exact best size, consider your lamp placement.

For example, if you plan to place it up on a mantel or shelf, you might opt for the 10- to 12-inch shade so people can’t see any of the hardware. (If you have the correct height shade based on your lamp measurements but still have issues, ensure you’re using the right harp size.)

Picking The Perfect Lamp Shade Width

To determine the perfect width for your lamp shade, use the following rule of thumb. The shade should be twice as wide as the widest part of the base. Therefore, measure across the broadest part of the base and multiply by two. If it’s 10 inches, you need a lamp shade that is 20 inches wide.

If your lamp base is round, measure straight across. If working with a square, measure the diagonal. This is a general rule, but you must always consider where you plan to put your lamp.

For example, if you’re placing it in an area with limited space, you might need a narrower shade. In this situation, at least make sure the widest part of your shade extends beyond the lamp base. The shade should go at least ½ an inch past the base on both sides.

Checking The Lamp Shade’s Top Diameter

For tapered or slanted lamp shades that are narrower at the top than the bottom, you also need to consider the top diameter. Choosing the correct width for the bottom of the shade should lead you to an adequate top diameter.

However, depending on the shade’s design and your lamp, this might not always be the case. Therefore, it’s worth knowing some general guidelines. Make sure the top diameter of the shade is at least equal to the width of the lamp base.

However, it should never be more than twice the lamp base’s width. So, if your lamp base is 10 inches wide, the top diameter of the shade should be between 10 and 20 inches.

Choosing The Right Lamp Shade Slant

The lamp shade slant or slope is not the same as the height (unless there’s no slant). The height of the shade is from top to bottom, measuring straight down vertically. But if the lamp shade is slanted, you measure the slope from the top to the bottom edge, following the slant.

As long as your diameter measurements match up correctly with your base, the slant will likely work fine size-wise. But it depends on your preferred style and how much light you want your lamp to throw. A wider slant will give off a wider pool of light, and a narrower one will do the opposite. (You’d likely notice this more if using opaque shades.)

A Quick Guide To Basic Lamp Shade Sizes

If you’re shopping online for lamp shades, sometimes the choices can be overwhelming. Narrowing down your options using size filters can help. Here’s a guide to help you choose the right options (based on the bottom diameter):

  • Mini — 6 inches or less
  • Small — 6 to 9 inches
  • Medium — 9 to 11 inches
  • Large — 11 to 15 inches
  • Extra-Large — over 15 inches

Tips For Buying The Right Lamp Shade

In addition to finding the right size lamp shade, there are other things to consider. The style, color, design, opacity, and fittings are all essential elements when choosing your shade.

  • Make sure you know what kind of lamp shade fitter is necessary for your lamp. Often, the base requires a particular fitter, and they aren’t interchangeable.
  • In general, a round or hexagonal shade looks best on a round base. A square or rectangular shade looks best on a boxy base.
  • Know exactly what you want your lamp to do. You might prefer a more translucent shade depending on the type and amount of light you need. However, an opaque shade is the better option if you’re going for a moodier vibe or need more directed light.
  • Bring your lamp with you when you’re shopping for a shade. You can try out styles and sizes then and there instead of carting the shades home to test them.
  • The width of the lamp shade should be roughly the same as the lamp base’s height.
  • In a pinch, for table lamps, multiply the lamp base height by 60% and 80% for a good lamp shade height range. For floor lamps, multiply the base by 30% and 50%.

What About The Right Lamp Shade For Floor Lamps?

If you’re looking for the best fitting shade for a floor lamp, you can follow the same general rules for the width. But for the height, consider a shade between 30% and 50% of the height of the floor lamp’s base. Simply multiply the lamp base height by 30% and 50%.

This step gives you a range to work with when choosing the best size shade. Your lamp’s placement and your design preferences will guide you the rest of the way.

Finding The Perfect Size Lamp Shade

If you find the perfect lamp for your space during your latest thrifting spree, don’t skip it just because it’s missing a shade. Or maybe you find a lamp base you adore, but the shade is horrid. These are easy design fixes; all you need to know is how to choose the right lamp shade size.

The general rule is to opt for a shade twice as wide as the broadest part of the lamp base. Then, go for one with a height roughly ⅔ the height of the lamp base. If measuring the total lamp (including the harp and bulb), find a shade approximately ⅓ the height.

Finding the perfect lamp shade size is critical to achieving the right look. Too tall, and your lamp can look off-kilter and top-heavy. But too short, and it can look awkward and expose the lamp hardware and bulb.

When in doubt, select a few sizes that measure up based on your lamp base size and try them out. Bringing your lamp with you when hunting for shades is a great way to save time and know you’re getting precisely what you want.

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Stacy Randall
Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent's former home, making it their own and learning a lot about life along the way.

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