Light Bulb Base Types Chart (E26, E12, GU10) | TaskHolt
Light Bulb Base Types Chart (E26, E12, GU10 & More)
A light bulb base size chart for the common screw and pin bases — E26, E12, E17, GU10, GU24, BR/PAR shapes — so you buy a bulb that fits.
Common bulb bases
| Base | Name | Typical use |
|---|---|---|
| E26 | Medium (standard US) | Most household lamps & fixtures |
| E12 | Candelabra | Chandeliers, decorative, night lights |
| E17 | Intermediate | Appliance, some ceiling fans |
| E39 | Mogul | High-wattage / commercial |
| GU10 | Twist-lock pin | Track & recessed spotlights |
| GU24 | Twist-lock pin | Energy-code fixtures |
| G4 / G9 | Bi-pin | Under-cabinet, accent, puck |
| BR30 / PAR38 | Reflector (E26 base) | Recessed cans, floodlights |
“E” bases are Edison screw; the number is the diameter in mm (E26 = 26 mm). “GU” bases twist and lock with two pins. Check the old bulb’s base before buying.
Convert brightness with the watts-to-lumens calculator. Shop LED bulbs, smart bulbs & ceiling lights.
Frequently asked questions
What is the standard light bulb base in the US?
E26 (medium Edison screw, 26 mm) is the standard household base for most lamps and fixtures.
What is the difference between E26 and E12?
E26 is the standard medium base; E12 is the smaller candelabra base used in chandeliers and decorative fixtures.