# A21 light bulb (E26 base)

> What size is an A21 light bulb?

- Category: Everyday objects › Light bulbs
- Kind: Modern device
- Basis: Philips product datasheet (Philips 16A21/PER/830/P/E26/DIM)
- Page: https://xemstudio.com/objects/a21-light-bulb/ · JSON: https://xemstudio.com/api/geometry?object=a21-light-bulb · Plain text: https://xemstudio.com/objects/a21-light-bulb/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 78 | 78 | 140 |

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

## 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).

## Sizes

| dimension | value |
|---|---|
| diameter | 78 mm (3.07 in) |
| max overall length | 140 mm (5.51 in) |
| base | E26 |
| reference product | Philips 16A21/PER/830/P/E26/DIM |

## Where the files are

- Philips: [Philips 16A21/PER/830/P/E26/DIM datasheet](https://www.assets.lighting.philips.com/is/content/PhilipsLighting/fp929001836904-pss-en_us) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/a21-light-bulb/index.json

- a21-light-bulb-envelope: [STEP](https://xemstudio.com/files/hardware/a21-light-bulb/a21-light-bulb-envelope.step) · [STL](https://xemstudio.com/files/hardware/a21-light-bulb/a21-light-bulb-envelope.stl) — Envelope Ø78 × 140 mm

## Questions

**How big is an A21 bulb?**

About Ø78 × 140 mm (reference product).

## Fits with

- [A19 light bulb (E26 base)](https://xemstudio.com/objects/a19-light-bulb/)
- [BR30 light bulb (E26 base)](https://xemstudio.com/objects/br30-light-bulb/)
- [BR40 light bulb (E26 base)](https://xemstudio.com/objects/br40-light-bulb/)
- [PAR30L light bulb (E26 base)](https://xemstudio.com/objects/par30l-light-bulb/)
- [PAR38 light bulb (E26 base)](https://xemstudio.com/objects/par38-light-bulb/)
- [G25 light bulb (E26 base)](https://xemstudio.com/objects/g25-light-bulb/)
- [MR16 light bulb (GU5.3 base)](https://xemstudio.com/objects/mr16-light-bulb/)
- [GU10 PAR16 light bulb (GU10 base)](https://xemstudio.com/objects/gu10-par16-light-bulb/)