Library › Everyday objects › Light bulbs ·

A21 light bulb (E26 base)

What size is an A21 light bulb? · Modern device · basis: Philips product datasheet (Philips 16A21/PER/830/P/E26/DIM)

Also called: a21 bulb size, a21 dimensions, a21 light bulb dimensions, bombilla A21 medidas, lâmpada A21 dimensões, A21 Lampe Maße, ampoule A21 dimensions

Exact dimensions. True size, with no printing tolerance added.

length
78 mm
width
78 mm
height
140 mm

Notes

  • A21: Ø78 mm, 140 mm maximum overall length, E26 base — figures from the Philips 16A21/PER/830/P/E26/DIM datasheet.
  • The shape code gives the diameter in eighths of an inch (A21); the ANSI C78 envelope limits are paywalled, so a typical current product is quoted. Other brands differ by a few mm in length.
  • The file is a cylinder envelope Ø × MOL (the bulb fits inside it).

A21 light bulb size chart

dimensionvalue
diameter78 mm (3.07 in)
max overall length140 mm (5.51 in)
baseE26
reference productPhilips 16A21/PER/830/P/E26/DIM

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

PhilipsPhilips 16A21/PER/830/P/E26/DIM datasheetwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

a21-light-bulb-envelopeEnvelope Ø78 × 140 mmSTEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=a21-light-bulb

A21 light bulb (E26 base), isometric render of a generated part
Render of a21-light-bulb-envelope from the free STEP; not to scale.

Fits with

Questions

How big is an A21 bulb?

About Ø78 × 140 mm (reference product).