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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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.