Understanding Lamp Base Codes: E26 and E27 Explained
If you’ve ever shopped for bulbs or lampshades online, you’ve likely seen “E26” or “E27” listed under specifications. These short codes are not random — they describe the socket type, which determines what kind of bulb fits your lamp.
Here’s a quick breakdown:
● E stands for Edison screw base, named after Thomas Edison.
● 26 or 27 refers to the diameter in millimeters of the screw base.
So, an E26 bulb has a 26 mm screw base, and an E27 bulb has a 27 mm one. That’s just a 1 mm difference — and in most cases, they are interchangeable.
However, there are still a few important differences worth knowing, especially if you want your lamp to be safe, stable, and compatible for the long run.
E26 vs E27: Are They Really the Same?
The Regional Standard
● E26 is mainly used in North America (US, Canada, Japan), where the standard household voltage is 120V.
● E27 is the European and international standard, used in Europe, Asia, Australia, and other regions with 220–240V systems.
Even though the bulb threads are nearly identical, the electrical rating differs:
● E26 bulbs are typically rated for 120V.
● E27 bulbs are rated for 220–240V.
So while an E27 bulb might physically screw into an E26 socket, or vice versa, you should always match the bulb to your local voltage standard for safety and performance.
How to Measure Your Lamp Holder Correctly
Before buying a new lampshade, it’s crucial to identify your lamp’s base and shade fitting type. Here’s a step-by-step guide:
1. Unplug your lamp and remove the bulb. Safety first!
2. Measure the diameter of the metal screw base (use a ruler or caliper).
- a. If it’s about 26 mm, it’s an E26 socket.
- b. If it’s about 27 mm, it’s an E27 socket.
3. Check the socket label or bulb printing — most manufacturers print “E26” or “E27” near the base.
4. Note the lamp’s mounting method: Does the lampshade sit above the socket, or attach from below with a ring?
5. Take pictures or note dimensions before ordering your replacement shade online — this helps ensure a perfect fit.
A little measuring now can save you a lot of frustration later.
Types of Lampshade Fittings
Lampshades aren’t one-size-fits-all. The fitting type determines how the shade attaches to the lamp. Here are the most common ones you’ll encounter:
1. Harp Fitting (Common in the US)
Used in many E26 lamps, a harp is a metal frame that holds the lampshade above the bulb. The shade is secured with a finial on top.
● Ideal for table or floor lamps with traditional designs.
● Works best with fabric or drum-shaped shades.
2. Uno Fitting
This type attaches directly to the lamp socket itself, below the bulb.
● Common in smaller lamps or reading lights.
● Available in both E26 and E27 versions.
● Great for space-saving designs.
3. Spider Fitting (with Reducer Ring)
A spider fitting is the most versatile — it fits over a harp but can also adapt to E26/E27 sockets using a reducer ring.
● Excellent choice for replacement shades.
● Compatible with most floor lamps.
4. Clip-On Fitting
Instead of connecting to the socket, the shade clips directly onto the bulb.
● Perfect for small accent or bedside lamps.
● Works with globe or candle-shaped bulbs.
When choosing a lampshade, always make sure the fitting type matches your lamp’s structure. A mismatched fitting can cause wobbling, overheating, or an unbalanced look.
How to Choose the Right Lampshade Size
Even if your socket fits perfectly, an incorrectly sized shade can make your lamp look awkward or unstable.
1. Here are three rules of thumb: Proportion matters:
- a. The shade’s height should be about two-thirds the height of the lamp base.
- b. The bottom of the shade should cover the lamp’s hardware but not block the bulb entirely.
2. Width and balance:
- a. The width of the shade should be roughly equal to the lamp’s height.
- b. For a floor lamp, a 16–18 inch diameter shade usually looks balanced.
3. Function over form:
- a. For reading lamps, choose narrower shades to direct light downward.
- b. For ambient lighting, go for wider or more translucent shades that diffuse light evenly.
Light Direction and Material: What to Expect
Different lampshade materials and shapes affect both the brightness and tone of your room’s lighting. More detailed information in Types of Lamp Shades.
| Shade Material | Light Effect | Recommended Use |
| Fabric | Soft, diffused light | Living room, bedroom |
| Glass | Bright, crisp light | Reading corners, study |
| Paper or Linen | Warm, cozy glow | Ambient or decorative lighting |
| Metal | Focused, downward light | Task or accent lighting |
Tip: If you’re using LED bulbs (especially dimmable ones), pairing them with fabric or linen shades gives a more natural, warm effect without glare.
When to Replace Your Lampshade
Even high-quality shades don’t last forever. Here are signs it’s time for a new one:
● The fabric has yellowed or cracked.
● The frame feels loose or rusted.
● The shade leans or wobbles no matter how you adjust it.
● The light looks dim or uneven.
Replacing your shade can instantly refresh your lamp — and your room.
Safety Tips When Changing Lampshades
1. Always unplug the lamp before removing the bulb or shade.
2. Avoid over-tightening screws or rings — it can crack the shade.
3. If using a metal frame shade, ensure it doesn’t touch the bulb directly.
4. Use the correct bulb wattage listed on your lamp’s label.
5. Never cover an open-top lamp completely; proper ventilation prevents overheating.
These small precautions make a big difference in lamp longevity and safety.
Final Thoughts
Choosing the right lampshade for your E26 or E27 floor lamp doesn’t have to be complicated.
Once you understand the socket type, fitting style, and proportions, finding a perfect match becomes almost effortless.Think of your lampshade not just as a cover, but as part of your home’s personality — and the right one will make your light shine beautifully, both functionally and aesthetically.
Frequently Asked Questions for Right Lampshade
Can I Use an E27 Bulb in an E26 Socket?
Yes, physically it fits, but make sure the bulb voltage matches your country’s standard (120V vs 240V). Using a mismatched bulb can shorten its life or cause overheating.
How Do I Know What Type of Lampshade Fitting I Have?
Check how the shade connects to your lamp:
● If there’s a metal frame and finial on top, it’s a harp fitting.
● If it screws directly onto the socket, it’s uno or spider.
● If it clips on the bulb, it’s clip-on.
What Size Lampshade Should I Get for My Floor Lamp?
For most standard floor lamps, a 16–18 inch wide shade looks proportional. For tall arc or tripod lamps, you can go larger (up to 20 inches).
Can I Clean My Lampshade with Water?
Only if it’s glass or metal. For fabric or paper shades, use a soft brush, lint roller, or vacuum with a low-suction nozzle. Avoid soaking — moisture weakens the glue or lining. More about how to clear your shade just check this article: How To Clean Lamp Shades.
Why Does My Lampshade Sit Crooked?
Usually because the fitting ring or harp is bent. Gently adjust the frame or replace the ring; avoid forcing the socket itself.