Lampshade Size Calculator
Enter the height of your lamp base up to the socket, the widest part of the base and the shade style. The calculator gives the bottom and top diameter, the shade height, the harp size and the finished lamp height.
- Shade diameter
- Shade height
- Harp size
Measure the base from the table to the bottom of the socket.
A balanced shade is about two thirds of the base height. The bottom of the shade should be about as wide as the base is tall, and at least twice the widest part of the base. A 45 cm base takes a shade about 45 cm wide and 30 cm tall, which hides the socket from a seated view.
Lampshade size chart
Drum shades. Search for a base height.
| Base (cm) | Shade width | Shade height | Harp |
|---|---|---|---|
| 20 | 20 | 13 | 11 |
| 25 | 25 | 17 | 14 |
| 30 | 30 | 20 | 17 |
| 35 | 35 | 23 | 20 |
| 40 | 40 | 27 | 23 |
| 45 | 45 | 30 | 26 |
| 50 | 50 | 33 | 28 |
| 60 | 60 | 40 | 34 |
| 70 | 70 | 47 | 40 |
Sizes in cm.
Base height and shade
Drum shade. Slide the base height.
The lamp is drawn to scale with its shade.
How to size a lampshade
Base to shade. Step through it.
Measure the base
To the socket.
Hold a shade over the base before you buy if you can. Proportions look different in a room.
Drum, empire or coolie
Shade styles. Compare them.
Straight sides.
Tapered.
Wide flare.
Wider bottoms spread light down onto tables and chairs.
Before you buy
Shade checks. Tick each item.
Tick each item as you go.
Check the fitting: harp, spider or uno fitter, or a clip-on for small shades.
What you get
Shade sizing. Each tile explains one result.
Diameter.
Diameter.
Shade.
Size.
Overall height.
A shade that is too small makes a lamp look top-heavy. Too large looks like a hat pulled down.
Frequently Asked Questions
No question matches that search.
How do I choose a lampshade size?
Make the shade about two thirds of the base height, and its bottom about as wide as the base is tall.
How wide should a lampshade be?
At least twice the widest part of the base and roughly equal to the base height.
What size harp do I need?
One that puts the bottom of the shade just below the socket, usually a little less than the shade height.
Should the shade cover the socket?
Yes. The bottom edge should hide the socket and bulb from a seated view.
What is the difference between drum and empire shades?
A drum has straight sides. An empire narrows towards the top.
Can a lampshade be too big?
Yes. If it reaches below the base neck, it looks heavy and blocks light.
How do I measure a lamp base?
From the table to the bottom of the socket, plus the widest part of the body.
Balanced light
Size the shade to the base and the room, and the lamp looks right and lights the space well.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.