Threaded screw base guide

E27

European medium screw

E27 is the common medium screw base in many 220–240 V markets. It looks almost identical to U.S. E26, so voltage and fixture certification matter.

Reviewed August 12, 2026
27 mm diameterNominal measurement · drawing not to scale
Connection
Threaded screw
Electrical context
Commonly paired with 220–240 V fixtures
Also called
European Edison screw, ES, European medium base

How to identify E27

  1. Look for E27 and a voltage marking on both bulb and fixture.
  2. The nominal thread diameter is 27 mm.
  3. Treat an imported lamp as an electrical system, not just a socket size.

Where it is commonly used

Imported lampsEuropean fixturesPendant lightsDecorative lamps

Common use is a clue, not proof. The fixture label and model documentation take priority over a visual match.

Bulb shapes sold with this base

You may see these shapes with a E27 base. The base code does not guarantee the bulb width, length, beam angle, or clearance.

A60G80ST64PAR38

Before you buy a replacement

  • Do not choose a replacement by physical fit alone.
  • Verify the fixture input voltage and the bulb voltage range.
  • Use products approved for the country where the lamp is operated.