How to determine the right lampshade size for a table lamp

What lamp shade size do I need for my table lamp?

A well-proportioned lampshade should balance the shape and size of the lamp base without overpowering it. As a starting point:

• For a slim lamp base, choose a lampshade with a width approximately equal to the height of the base.

• For a wider lamp base, choose a shade approximately 10 cm (4") wider than the widest part of the base—around 5 cm (2") on each side.

• The lampshade’s height will usually be approximately 30–40% of the combined height of the lamp and shade.

These are useful guidelines rather than rigid rules. The shape of the base, the room and your preferred proportions will also influence the final choice.

Grab a tape measure and follow the steps below. If you are still uncertain after measuring, you are welcome to contact us for personal sizing advice.

When choosing the correct lampshade size, you will need to first of all consider the shape of your lamp base. Lamp bases can have many shapes, but the most common ones can essentially be narrowed down to a slim type of profile or a larger profile. Let's take a look at these two lamp base styles.

Slim Style Lamp Base

If you have a table lamp base with a slim shape then check the height of the lamp base (b in the above picture). Start from measuring right under where the bulb fits, but do not include the fitting itself. Then let the tape measure go all the way to the bottom of the table lamp. You now have the lamp's height (b). Let's imagine this measurement is 12" (30cm). 

How wide should the lampshade be if the lamp base is 12" high?

The lampshade's width (a in the above picture) should be (approximately) equal to b, the lamp's height. Therefore, if that height is 12" then the lampshade should be 12" wide.

Bear in mind, this is a rule of thumb and not exact science. To be precise, when you have a very slim and tall lamp base type, it's sometimes advisable to choose a lamp shade that is slightly smaller than the lamp's height. That's because the profile of the lamp base is slim, so you might want to keep that slender look and avoid overpowering the base with a big lampshade.

For example, if your table lamp is 24" high (60cm), according to the rule you'd have to choose a 24" wide lampshade. In most cases that is likely to be too wide.

Use the above rule as a guidance, but be prepared to break that rule if common sense suggests something different.

Medium and large width lamp base

If your lamp base is not slim and has instead a considerable width, then proceed by measuring the widest part of the lamp base (c in the above picture).

To have a balanced look, the light shade should be roughly 2" (5cm) wider on both sides of the table lamp's widest part. 

For example, if the widest part of the lamp base (c) measures 8" (20 cm), add approximately 4" (10 cm) in total. A lampshade around 12" (30 cm) wide should provide a balanced proportion.

Lampshade height

Once you have established the right width for your light shade, it's time to choose the height.

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The height of the light shade should be 30% - 40% the overall height of lamp base height + lampshade height. 

Although there are various ways to make this calculation, we find the following to be the easiest one. Let's assume we are using the 60% and 40% proportion.

Measure the height of the lamp base and divide that number by 6. Then multiply the result by 4, this calculation will tell what height you need for the table lampshade. Easy enough? Let's see an example.

Let's assume the lamp base is 18" (45cm) high.

We divide that number by 6, the result is 3" (7.5cm).

We then multiply that number by 4, the result is 12" (30cm).

Based on these calculations your lampshade should be 12" (30cm) high.

With this choice of lampshade height, the light shade will be 40% of the overall height (lamp base + lampshade) and provide a balanced look.

Having said that, there can be other factors that need to be considered, especially when your lamp base has a harp.

To establish the ideal height, measure the harp vertically, as pictured above. The shade will usually need to be approximately ½–2" (1.3–5 cm) taller than the harp so that the fitting and other non-decorative hardware remain concealed.

For example, an 8" (20 cm) harp may suit a shade approximately 8½" (21.5 cm) high. The exact allowance will depend on the shape of the shade and where it sits on the fitting.

How to measure an oval lampshade

Unlike a round drum shade, an oval lampshade has three important measurements: width, depth and height.

• Width: measure across the widest part of the shade from left to right.

• Depth: measure from the front to the back.

• Height: measure vertically from the bottom edge to the top edge.

Check all three measurements when comparing an oval shade with your lamp base. The narrower depth makes an oval lampshade particularly useful where space is limited, such as on a console table, bedside table or narrow piece of furniture.

Explore our oval lampshades, handmade to order in the UK in a choice of colours and decorative finishes.

Adoro Décor standard lampshade sizes

Once you have calculated an approximate width and height, compare your measurements with our standard drum lampshade sizes:

A 30 cm shade often works well with smaller and medium-sized table lamps. If your lamp has a wider or more substantial base, a 40 cm lampshade may create a more balanced proportion.

Our Home Collection includes 20 cm, 30 cm and 40 cm options. Larger 40 cm, 50 cm and 60 cm lampshades are available within our Luxury Collection.

We can also make selected shades in alternative diameters, including 25 cm, 35 cm, 45 cm, 55 cm, 65 cm and 70 cm. Different heights may also be possible, depending on the design.

Ready to choose your lampshade?

Once you know the approximate size you need, you can:

• Browse 30 cm lampshades for smaller and medium-sized table lamps.

• Browse 40 cm lampshades for wider or more substantial bases.

• Explore drum lampshades in an extensive choice of colours, patterns and linings.

• Shop all handmade lampshades if you would prefer to compare the full collection.

Every Adoro Décor lampshade is handmade to order in the UK, with custom sizes available on request.

Still unsure which size to choose?

Lamps come in many different shapes, so the most suitable size cannot always be determined by a formula alone. If you would like personal advice, contact us with:

• A photograph of the complete lamp base

• The height of the base, excluding the bulb fitting

• The width at its widest point

• The harp height, if your lamp uses one

• The lampshade size you are considering

We will be happy to help you assess the proportions before you order.