What bulb base does a recessed light take?

Q: What bulb base does a recessed light take?

Most standard recessed light cans use an E26 medium screw base with a BR30 or PAR38 flood bulb. Some retrofit trim kits use GU10 twist-lock bases. Check inside the can or on the trim ring label to confirm.

Standard recessed cans (4″ and 6″) use an E26 medium screw base with a BR30 or PAR38 flood-shape bulb. Retrofit trim kits may use a GU10 twist-lock base instead.

The two common types

E26 with BR30 or PAR38 bulb

Most recessed cans installed before 2010 have a brass E26 socket inside the can housing. The standard replacement bulb shapes are:

BR30 — 3.75″ diameter flood, fits most 6″ cans. Common for general lighting.
PAR38 — 4.75″ diameter, narrower beam angle, used in 6″ cans for accent or directional lighting.

Reference: E26 medium screw spec

GU10 twist-lock

Many retrofit LED trim kits (sold as drop-in replacements for old incandescent cans) use a GU10 push-and-twist base. The bulb has two pins 10 mm apart and locks with a 90° turn. GU10 LED bulbs are compact and do not require a separate reflector can.

How to identify which you have

Turn off the circuit breaker for the fixture.
Remove the existing bulb. If it unscrews, it's E26. If it pulls out with a quarter-turn, it's GU10.
Look at the socket interior — E26 has a brass screw cup; GU10 has two small rectangular slots.

Integrated LED fixtures

Many recessed fixtures sold after 2015 are integrated LED — the light engine is built into the trim and there is no replaceable bulb socket at all. If you cannot see any socket after removing the trim ring, your fixture is likely integrated. Contact the manufacturer for a replacement module.