Posted by Sam on Jul 17th 2018

Light Bulb Base Chart

Types of Light Bulb Bases

Find the  light bulb you need using this visual light bulb base chart and detailed illustrations of general light bulb bases, fluorescent bases and specialty halogen base types.

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Light Bulb Base Chart

What is the Difference between Light Bulb Bases?

There are tens of unique bases for light bulbs. The most familiar is the Edison screw base found on most incandescent bulbs and many halogencompact fluorescent, HID and now LED bulbs.

The common terms are medium, intermediate, candelabra and mogul. However, because the light industry likes mysterious codes, you may also see E26, E12, E39, etc. E obviously is for Edison. The number after the E is the diameter of the base in millimeters (mm).

Here are the most common Edison base names, codes and applications:

NameCodeDiameter (mm)Applications
MogulE3939 mm
MediumE2626 mmCommon Household Bulbs
IntermediateE1717 mmAppliances. Old Christmas Lights
CandelabraE1212 mmChandeliers. Ceiling Fans.
Mini CandelabraE1111 mm
MiniatureE1010 mm
MidgetE55 mm

The large Mogul bases found on higher wattage incandescent and HID bulbs are E39.

Most Edison base bulbs are called "single contact" because there is one contact button at the center of the base.