Finding the right bulb for your fixtures can seem like a guessing game. With so many different sizes, base types, numbers and letters associated with bulbs, how are you supposed to keep it straight? Even if you know which type of bulb you need, finding it among the sea of light bulb options can be challenging. An E12 bulb refers to a specific base type, but it comes in different types of bulbs to give you some choice in how you light your fixture.

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What Is an E12 Bulb?

E Stands for Edison

Let's start with the "E" portion of the name. The letter stands for Edison, which describes the type of base, and is not to be confused with the vintage-looking Edison-style bulbs you see in many fixtures. On these bulbs, Edison refers to the Edison Screw base, sometimes abbreviated as ES base. Thomas Edison developed the screw-in light bulb base that's still used on today's light bulbs. When you need an E12 bulb, you're looking for that standard screw-in base. Using the standard Edison base makes it easy to mix and match light bulbs and fixtures. As long as you buy the right size of base for your fixture, the bulb should work.

Size of the Base

The 12 portion of the base name refers to the size of the base. It's the diameter of the screw base in millimeters, so an E12 light bulb has an Edison Screw base that's 12 millimeters in diameter. It's also known as a candelabra-style bulb. Think of chandeliers, night-lights or candelabra-style lamps with the smaller bulbs to envision an E12 bulb base. For reference, your standard light bulb that goes into many fixtures and lamps uses an E26 base. That means it's 26 millimeters in diameter at the base.

Bulb Types

E12 only describes the base. The bulb itself can come in different sizes, shapes and types, which makes finding the right bulb for your fixture a little trickier. You can find bulbs with E12 bases featuring incandescent, CFL and LED lighting technology to fit your preferences and needs for particular fixtures. Some bulbs may come with clear glass, while others have frosted or colored glass. Just like larger bulbs, the E12 bulbs come in different types of light, such as soft white, bright white and daylight. You can even find dimmable E12 bulbs for specialty fixtures.

The bulb itself usually has another letter and number combination to describe it. For example, C7 bulbs have the candelabra-style E12 base. These bulbs are small and rounded. They're often used in decorative lighting or chandeliers. B10 bulbs have a wider middle tapering down to a pointed end, similar to a candle flame shape. You see this type of bulb on some chandeliers and in night-lights.

A number of specialty light bulbs also come with the E12 candelabra base. For example, T4.5 bulbs have a tubular shape that's the same width from top to bottom. Other bulbs might have different shapes or special designs and features to customize the look in your fixtures. Make sure the bulb has the same size base as your fixture, and you can get creative with the specific bulb you choose.