18650 lithium cell — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/18650-cell/  (CC BY 4.0)
Basis: industry standard (IEC 60086 naming); nominal values
Catalog version: 2026-10-20

Overall (mm): length 65, width 18, height 18
- Nominal Ø18 × 65 mm; real cells run Ø18.2–18.6 mm and 65.0–65.3 mm, and protected cells up to ~69 mm long. Design holders for Ø18.6 and 65.5 unless you know the cell.
- Button-top adds about 0.5–1 mm; flat-top is the common unprotected form.

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: List of battery sizes — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/List_of_battery_sizes

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/18650-cell/index.json
API: https://xemstudio.com/api/geometry?object=18650-cell