A-Type Standard LED Light Bulbs Customer Reviews

What Is an A-Type LED Light Bulb?

A-shaped bulbs are one of the most popular bulbs used in the home. They are so popular the A-shape is probably what comes to mind when someone says light bulb. To tell the difference between one A-shaped bulb and another, the bulbs are classified based on their diameter.

A-shaped bulbs are recognized by their traditional pear shape. Since they are used so widely, most A-type bulbs have a medium screw base. This base simply twists into the fixture where the bulb is used. Some A-type bulbs also have European medium screw bases, and twist and lock bases.

Types of A-Style Bulbs

Type A bulbs come in the traditional forms of incandescent, halogen and LED. Though there are differences in the benefits and performances of these technologies, the appearances stay mostly the same.

A15 vs. A19 vs. A21 vs. A23

The main difference between the A-style bulbs (A15, A19, A21, A23) is their diameter. The A23 typically has a higher wattage than the other A-style bulbs, as well.


With a diameter of 1.875 inches, A15 bulbs are the smallest of the A-shaped family. Their most popular use is in signs and decorative lighting.


The A19 is the most commonly used A-shaped bulb. From lamps to ceiling fixtures, bathroom vanities to sconces, and so much more, there’s a use for A19 bulbs in every room of your house. The A19’s diameter is approximately 2.4 inches.


After A19, A21 bulbs are the next most popular choice. With a diameter of about 2.6 inches, they are just slightly wider than A19 bulbs. Because of this similarity, A21 bulbs can be found in most of the same places A19s are, with their most popular use being around the home.


A23 bulbs are the largest of the A-shaped bulbs with a diameter of 2.875 inches. An A23 bulb typically has higher wattage than other A-shaped bulbs. This higher wattage makes the A23 a good choice for commercial uses that call for the traditional A-shape.