PAR38 Bulb
A parabolic aluminized reflector bulb 4.75 inches in diameter. Produces a focused, controlled beam — commonly used for outdoor floods and track lighting.
PAR stands for parabolic aluminized reflector — a precise mirror shape inside the bulb that produces a much more controlled, defined beam than BR bulbs. The "38" means 38 eighths of an inch in diameter (4.75 inches or 120mm), making this one of the larger common bulb sizes.
PAR38s excel where you need directional light over distance: lighting up a driveway from under an eave, spotlighting a tree from 20 feet away, or providing focused wash on a retail display. They're available in beam angles from tight 15° spots to wider 60° floods, so you can match the beam to the application.
The LED versions of PAR38 have been particularly successful because the original halogen PAR38s were enormous energy hogs — often 90-150W. An LED PAR38 delivers the same light output at 15-18W, which makes upgrading outdoor flood lights one of the highest-impact energy savings moves you can make.
Specifications
| Diameter | 4.75 in (120mm) |
| Beam angles | 15° spot to 60° flood |
| Common base | E26 |
| Typical use | Outdoor floods, track, landscape |
Related Terms
- BR30 Bulb
A bulge reflector shape 3.75 inches in diameter, designed for recessed can fixtures. Produces a wide, even flood of light directed downward.
- Beam Angle
The angle at which light spreads from a bulb. Narrow angles (15-30°) create spotlights; wide angles (60-120°) create flood light.
- E26 / E27 Base
The standard Edison screw base used in most household lamps and fixtures. E26 (26mm) is the North American version, E27 (27mm) is the European equivalent.