MR11 bulb shape and size

Dimensions

What MR11 tells you

Shape

small multifaceted-reflector bulb

Nominal diameter

1.375 in (35 mm)

Typical bases

GU4

Common uses

display lights, landscape lights, compact spotlights

The diameter is part of the naming system, not a full dimension drawing. Individual models can differ in overall length, neck profile, optics, and manufacturing tolerance. Use the maker's drawing when the fit is close.

At the fixture

Four other details to record

1. Read the base code and voltage on the old lamp or fixture label.
2. Compare the published maximum diameter and overall length with the available space.
3. Record lumens, beam angle where relevant, color temperature, and dimming behavior.
4. Look for the enclosure, location, temperature, or vibration rating required by the fixture.

Easy to miss

Notes for MR11

• MR11 describes the reflector, not the base or voltage.
• Pin spacing and transformer compatibility must match.

Sources

Reference method

BulbMatch uses the U.S. eighth-inch naming convention as a nominal shape reference and keeps model-specific dimensions separate.

• LEDVANCE guide to light bulb shapes, types, and sizes
• U.S. Department of Energy: lumens and lighting choices