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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What is the Difference between Light Bulb Bases?
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:
|Medium||E26||26 mm||Common Household Bulbs|
|Intermediate||E17||17 mm||Appliances. Old Christmas Lights|
|Candelabra||E12||12 mm||Chandeliers. Ceiling Fans.|
|Mini Candelabra||E11||11 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.