A19 bulb shape
A19 is the standard pear-shaped household bulb — 2.375 inches in maximum diameter and paired with an E26 base in North America.
Exact specs
| Shape code | A19 |
|---|---|
| Maximum diameter | 2.375 in (60 mm) |
| Length (approximate) | 4.13 in (105 mm) |
| Common base pairing | E26 (NA), E27 (EU) |
| Typical use | Table lamps, ceiling fixtures, general indoor lighting |
What fixtures commonly use it
A19 is the default shape for most table lamps, reading lamps, floor lamps, and open ceiling fixtures. If a fixture says "standard bulb" it almost certainly accepts A19.
What it's interchangeable with
A21 uses the same E26/E27 base and can often physically fit, but it is wider — check that the shade or globe housing has enough clearance.
What it's NOT interchangeable with
A19 shape cannot substitute for BR30 or PAR38 in reflector fixtures — the beam pattern and directionality differ substantially.
Common mistakes
- Buying A21 and finding it too wide for a tight shade or fixture globe.
- Confusing shape code with base code — an A19 bulb still needs to specify its base (A19/E26 or A19/E27).