What size ceiling light cover do I need?

You need a ceiling light cover that matches the fitter diameter and the attachment, not the width of the old glass at its widest point. Measure the lip the screws, twist lock, or center finial actually grab. Then confirm the new cover is deep enough to clear the bulb. A cover that is even a small step off the fitter will not seat.

What to measure

1. Fitter opening: the metal ring or neck, across the inside of the lip.
2. Attachment: thumbscrews, a twist-lock notch, or a threaded center stud and finial.
3. Depth: the bulb must not touch the glass.
4. If the old cover is gone, measure the metal fitter that is still on the fixture.

Covers are not sized by room. Room size picks the whole fixture. The cover only has to fit the fixture you already have.

When a new fixture is the simpler match

51lighting sells complete ceiling lights, so the shade and the fitter already belong together:

• Bowl-shaped chrome crystal flush mount
• Mini round crystal flush mount for a hallway
• Crystal raindrop flush mount LED ceiling light
• Ceiling lights

Is the size printed on the glass?

Sometimes on a sticker or the fixture manual, almost never on the glass itself. Measure the fitter.

Updated 8 October 2026.