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?
There are tens of unique bases for light bulbs. The most familiar is the Edison screw base found on most incandescent bulbs and many halogen, compact 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:
| Name | Code | Diameter (mm) | Applications |
| Mogul | E39 | 39 mm | |
| 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 | |
| Miniature | E10 | 10 mm | |
| Midget | E5 | 5 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.
7 comments
looking for Phillips 75 W Reflector R20 Duramax 120v E3 Holland. Or Feit 50 or 75w 130v china. Recessed in kitchen. Led equivalents ok. Dimmer a must. Need 12 or so.
916-932-3530.
Hey,
Great informative article. Looking for some LED E12 bulbs can you help me?