An A19 LED bulb is the most common type of LED bulb used in homes. A19 bulbs are members of the A-type light bulb family. The bulb gets its name from having a pear shape also known as an “A” shape. The diameter of an A19 bulb is 2.375. A19 bulbs are versatile and have a low cost making them a popular choice for many homes.
The main difference between the A19 and A21 LED bulbs is the size of the bulbs. An A19 and A21 both have a pear shape. However, the diameter of the A19 is around 2.375 inches. The diameter of the A21 is 2.625. Another difference is the base height. The A19 bulb measures a base height of approximately 4.13 inches tall. The A21 differs in that the base height is 5 inches tall.