A19 refers to the shape and size of the bulb itself. “A” stands for Arbitrary — just the name of the shape that’s familiar to most of us. “19” refers to the size — in this case, 19/8″ (or 2 3/8″) across. E26 refers to the type and size of the base — the part that goes into the light socket.

Is A19 and E26 the same?

All A19 lamps have an E26 base, but not the other way around The standards that govern the dimensions and design of A19 light bulbs also dictate that it must use an E26 screw base. In other words, all A19 light bulbs also have an E26 base.

What is an A19 bulb used for?

From left to right: A19 LED filament bulbs in ceiling fan fixture, a 19 gold-tint LED filament bulb in porch light fixture, A19 LED fireworks bulbs in string lights, and a A21 LED bulbs in bedroom lamps. Standard/arbitrary (A) bulbs are the most widely used and thought of when it comes to household lighting.