What is an E27 Socket? The Complete Guide for 2026

Emily Carter

By Emily Carter · Updated July 2026 · 6 min read

Short answer: An E27 socket is a standard Edison screw light bulb fitting with a 27mm base diameter — the most common bulb socket used in homes across Europe, Asia, and most of the world. "E" stands for Edison (the screw design), "27" means 27 millimeters wide. If you've ever screwed a regular bulb into a lamp at home, you've probably used an E27 socket.

The E27 socket fits everything from a basic table lamp to a ceiling fan light, a WiFi security camera, or an 80W garage LED. It's the universal standard for screw-in bulbs — and if you're shopping for any light fixture that says "E27," this guide will tell you exactly what it means, how it compares to E26, and how to pick the right bulb.

Below, we cover E27 socket sizes, E27 vs E26 differences, whether you can swap bulbs between them, and the best E27-compatible lights for your room.

Contents

What Is an E27 Socket?

An E27 socket is a screw-in light bulb fitting where the bulb has a threaded metal base that's 27 millimeters across. You twist it clockwise to install, counter-clockwise to remove — same motion you've done a thousand times with household bulbs.

The "E" stands for Edison screw, named after Thomas Edison who patented this design back in the 1880s. The number tells you the diameter: E27 = 27mm, E26 = 26mm, E14 = 14mm, and so on. Simple system — the letter tells you the type, the number tells you the size.

Diagram of an E27 Edison screw bulb base showing 27mm diameter measurement — standard E27 socket type used worldwide
The "27" in E27 means the base is 27mm wide. The Edison screw design hasn't changed in over 100 years.

E27 is the default bulb fitting in most of the world — Europe, UK, Australia, Asia, Africa, and parts of South America. In North America and Japan, the equivalent is E26 (26mm, rated for 110–120V instead of 220–240V).

So when a product says "E27 socket," it just means: this fixture takes a standard screw-in bulb with a 27mm base. No special adapter, no bayonet mount — just the classic twist-in design that's been around for over a century.

E27 Socket Sizes & Specifications

Specification E27 Socket Value
Base type Edison screw (single-contact)
Base diameter 27mm (±0.3mm tolerance)
Thread pitch 3.6mm (same as E26)
Standard voltage 220–240V AC (also available in 110V variants)
Max wattage (incandescent) Typically 60W (LED versions use much less)
Operating temperature −20°C to +100°C
Compatible bulb types LED, CFL, halogen, incandescent
IEC standard IEC 60061 (sheet 7004-21-9)
Also known as ES, E27 socket type, Edison screw 27mm

In practice: if a bulb says "E27" or "ES" and your fixture runs the same voltage, it'll fit. A modern 10W LED can safely go in a socket rated "Max 60W."

E27 Light Bulb Socket: Types & Uses

E27 Socket Type Where You'll Find It Typical Use
Standard lamp socket Table lamps, floor lamps Reading light, ambient lighting
Ceiling fixture socket Pendants, flush mounts Room lighting, kitchen, hallway
Ceiling fan light socket Ceiling fan light kits Combined light + airflow
Smart bulb socket WiFi bulbs, smart home devices App-controlled lighting
Security camera socket Bulb-style cameras Hidden monitoring
E27 bulb holder Bare sockets, work lights Garages, workshops, utility rooms

E26 vs E27: What's the Difference?

Feature E27 Socket E26 Socket
Base diameter 27mm 26mm
Standard voltage 220–240V 110–120V
Thread pitch 3.6mm 3.6mm (identical)
Regions Europe, UK, Asia, Australia, Africa USA, Canada, Japan, Mexico
Physically interchangeable? Often yes — the 1mm difference rarely prevents fitting
Electrically interchangeable? ⚠️ No — voltage mismatch will blow the bulb

Always match the voltage to your country's mains supply. The Lumwell 80W LED Garage Light handles 85–265V — one of the few true dual-fit options.

Can I Use an E27 Bulb in an E26 Socket?

Scenario What Happens
E27 bulb (220V) in E26 socket (120V supply) Bulb turns on but very dim
E26 bulb (120V) in E27 socket (220V supply) ⚠️ Bulb blows instantly
E27 LED bulb (wide-voltage 85–265V) in E26 socket ✅ Works fine
E26 LED bulb (wide-voltage 85–265V) in E27 socket ✅ Works fine

Most modern LED bulbs are rated for wide voltage (85–265V). If it says "100–240V," you can safely use it in either socket.

Where Are E27 Sockets Used?

Common household items that use E27 sockets — table lamp, ceiling fan light, WiFi bulb camera, garage light, smart bulb all using the same E27 light bulb socket
Table lamps, ceiling fans, security cameras, garage lights — they all use the same E27 socket.

How to Choose an E27 Light Bulb

1. Match the Voltage

220–240V regions: buy E27. 110–120V regions: buy E26 — or wide-voltage LEDs (85–265V) that work anywhere.

2. Pick the Right Wattage

Table lamp: 8–15W LED. Ceiling fixtures: 12–20W. Garage/workshop: 40–80W LED.

3. Choose the Color Temperature

Color Temp Appearance Best For
2700K Warm white Bedrooms, living rooms ✅
3000K Soft white Kitchens, hallways ✅
4000K Cool white Offices, workspaces
5000K+ Daylight Garages, workshops

How to Install an E27 Bulb (7 Steps)

  1. Turn off the power.
  2. Let it cool — 5–10 minutes.
  3. Unscrew the old bulb counter-clockwise.
  4. Check the socket for damage.
  5. Screw in the new bulb clockwise.
  6. Tighten until snug.
  7. Restore power and test.
Step-by-step guide showing how to install an E27 light bulb — turn off power, unscrew old bulb counter-clockwise, screw in new E27 bulb clockwise
7 steps, 60 seconds, zero tools.

Best E27-Compatible Lights from Lumwell

All three screw into a standard E27 socket with zero rewiring:

Three Lumwell products that use E27 sockets — ceiling fan light with remote, WiFi bulb security camera, and 80W LED garage light, all fitting standard E27 light bulb socket
All three screw into a standard E27 socket. No electrician needed.

Frequently Asked Questions

Are E27 and E26 the same bulb?

No, but very close. E27 = 27mm base, 220–240V. E26 = 26mm base, 110–120V. Same thread pitch — but voltage mismatch will blow the bulb. For dual-fit, see the 80W LED Garage Light.

Is the E27 a standard light socket?

Yes. Default fitting in most European, Asian, African, and Oceanian countries. In North America and Japan, the equivalent is E26.

Is an E27 bulb a regular bulb?

Yes. In Europe, Asia, and most of the world, "regular bulb" means E27. In North America, it means E26.

What size is an E27 socket?

27mm base diameter, 3.6mm thread pitch. Only the diameter matters for compatibility.

Can I use an E27 bulb in an E26 socket?

Physically yes — the 1mm difference rarely prevents fitting. Electrically, match the voltage. Wide-voltage LED bulbs (85–265V) work safely in both sockets.

Can I use an E27 bulb in an E14 socket?

No. E14 is 14mm — much smaller. They won't fit without a rare step-up adapter.

Are E27 bulbs being phased out?

Incandescent E27 bulbs are being phased out. LED E27 bulbs are more popular than ever — 80% less energy, 10–25x longer life, same socket.

Infographic summary of E27 socket key facts — 27mm diameter Edison screw, 220-240V standard voltage, E27 vs E26 comparison, most common light bulb socket type worldwide
That's E27 in 60 seconds: 27mm Edison screw, 220-240V, the most common socket in the world.

The Bottom Line

E27 is the most common light bulb socket on the planet — 27mm Edison screw, standard 220–240V in Europe/Asia. The most common mistake is mixing up E27 and E26 voltages, or using indoor bulbs in outdoor fixtures.

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