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Home » A19 vs A21 Light Bulbs: What are the Differences?

A19 vs A21 Light Bulbs: What are the Differences?

A19 vs A21 Light Bulbs

The decision to switch from incandescent light bulbs to LED bulbs was an easy one. The next step is to unravel the huge variety of numbers and letters to find the right light bulb for your home or office. Two in particular that you would think are almost identical are the A19 and the A21.

The first part to understanding light bulbs is the letters and numbers. The letter refers to the shape and the number the size. ‘A’ light bulbs are the traditional pear-shaped light bulbs. The larger the number, the bigger the diameter of the bulb.

In the comparison chart below, you can see the exact differences between the A19 vs A21.

A19 vs A21 – Side by Side Comparison




Image A19 Light Bulb A21 Light Bulb
Height 3.9-4.73 inches 4.1-5.4 inches
Width 2.4 inches 2.6 inches
Average Brightness Up to 1,600lm Up to 1600lm
Average Watts 9.5W 15W
Incandescent Equivalent 60W 100W

Because of the size difference, the main thing you need to consider is the type of light fixture you have. The smaller 2.4-inch A19 will fit in practically any light fitting. The A21 has a 2.6-inch diameter and is better suited to lamp holders. The length might make a difference, depending on how much you want the bulb to protrude or not. The A19 and A21 have an E26, screw-in base, which means in terms of their connection, they are interchangeable.

The power consumption is a more considerable difference. The A21 uses an average of 15W (100W incandescent equivalent), whereas the A19 uses just 9.5W, or a 60W equivalent. This will vary from brand to brand and so will the average brightness. Both the A19 and the A21 have up to 1600 lumens. If you are looking for dimmable LED light bulbs, this might not be so relevant.

A19s and A21 on the Market Today

To get a clearer picture of the similarities and differences between these LED bulbs, we have taken a look at the Philips A19 and the Philips A21.

The Philips A19

For the best savings, you can choose from the 4 pack or 6 pack. They are 2.5 inches in diameter and 4.7 in height. They use 8.8W (like a 60W incandescent bulb) and have 800lm. They give off a warm glow with 2,200-2,700K, so good for relaxing areas. These are frosted, dimmable bulbs that don’t flicker. You can expect an average lifespan of 15,000 hours.

The Philips A21

Philips has chosen to make this bulb larger than average at 3.07 inches in diameter and 5.51 inches in height. However, it is still frosted, dimmable, flicker-free, and available in packs. It’s a 12W light bulb, equivalent to 75W, and has 1,100lm and 2,700K. Again, it offers a warm glow in rooms, but Philips has specified the lamp holder use.

Read next – A15 vs A19 Light Bulbs: What is the Differences?

The Final Verdict

The A21 will be the right choice for many but we prefer the A19. The size makes this light bulb more suitable for different uses. Using less energy means your electric bill can be kept lower, plus they are generally cheaper.