# Title: What Is the Standard Light Bulb Base?


## Author: OroDwell


## Description: The standard light bulb base in the United States is the E26 medium screw base, measuring 26 millime...


## URL: https://www.orodwell.com/blogs/ideas-inspiration/standard-light-bulb-base


## Metafields 

- title_tag: What Is the Standard Light Bulb Base?
- description_tag: The standard light bulb base in the US is the E26 medium screw base at 26 millimeters. Learn how E26 compares to E12, A19, and other socket types.
- faq_json: [{"q":"Are E12 and A19 bulbs the same?","a":"No. E12 is a base size measuring 12 millimeters in diameter, while A19 is a bulb shape measuring about 2.375 inches at its widest point. An A19 bulb typically has an E26 base, not an E12. The two codes describe different parts of the bulb. E12 bases are common in chandeliers and small decorative fixtures. A19 bulbs are general purpose household bulbs used in table lamps and ceiling lights."},{"q":"Which type of bulb is better, A19 or A21?","a":"Neither is universally better. A19 and A21 bulbs both usually use E26 bases, but the A21 has a larger diameter of about 2.625 inches. A21 bulbs can often accommodate higher wattages and produce more light. A19 bulbs fit more easily in smaller shades and enclosed fixtures. Choose A19 for standard lamps and A21 for larger spaces or fixtures with more clearance."},{"q":"Can I use an LED A19 bulb in any fixture?","a":"You can use an LED A19 bulb in any fixture with a matching E26 socket and enough physical clearance for the bulb. Check the fixture label for maximum wattage and enclosed fixture ratings. If the fixture is on a dimmer, select a dimmable LED bulb. The bulb must not touch the shade or globe. Integrated LED fixtures do not require a replacement bulb at all."},{"q":"What base does the A19 bulb fit?","a":"An A19 bulb typically fits an E26 medium screw base socket. The E26 base measures 26 millimeters in diameter and is the standard household socket in the United States. Most A19 bulbs screw directly into table lamps, ceiling fixtures, and open pendants. Always confirm the fixture socket is E26 before buying A19 bulbs."},{"q":"How can I tell what size my light bulb base is?","a":"Measure the threaded metal base diameter in millimeters. An E26 base measures 26 millimeters, an E12 measures 12 millimeters, and an E17 measures 17 millimeters. You can also compare the old bulb to a known E26 household bulb. Most fixtures have a label near the socket listing the base type or maximum wattage. When in doubt, measure the socket opening."}]