Watch battery size chart: every common coin cell compared
The code tells you everything once you can read it: for CR types, the first two digits are the diameter in millimeters, the last two are the thickness in tenths of a millimeter. A CR2025 is 20 mm across and 2.5 mm thick. Here's the full reference in one place.
Lithium (CR) — 3.0V
What most digital watches use.
| Code | Diameter | Thickness | Approx. capacity |
|---|---|---|---|
| CR1216 | 12.5 mm | 1.6 mm | ~25 mAh |
| CR1220 | 12.5 mm | 2.0 mm | ~38 mAh |
| CR1616 | 16 mm | 1.6 mm | ~55 mAh |
| CR1620 | 16 mm | 2.0 mm | ~78 mAh |
| CR2016 | 20 mm | 1.6 mm | ~95 mAh |
| CR2025 | 20 mm | 2.5 mm | ~165 mAh |
| CR2032 | 20 mm | 3.2 mm | ~230 mAh |
Silver oxide (SR) — 1.55V
Common in analog quartz and ana-digi.
| Code | Also known as | Diameter | Thickness |
|---|---|---|---|
| SR621SW | 364 | 6.8 mm | 2.1 mm |
| SR626SW | 377 | 6.8 mm | 2.6 mm |
| SR920SW | 371 | 9.5 mm | 2.0 mm |
| SR927W | 399 | 9.5 mm | 2.7 mm |
Alkaline (LR) — 1.5V
Cheaper same-size stand-ins for SR: LR41 fits SR41's slot, LR44 fits SR44's. They cost less, hold less, and are the chemistry most likely to leak in storage — the full trade-off is in the battery codes guide.
Reading the table like an engineer
Capacity scales with volume, which is why a CR2032 holds roughly 2.5x a CR2016 despite the same diameter — and why the maker's choice of cell IS the battery-life spec. It's also why substituting thicknesses fails mechanically: the bay and its contacts are built for one height (the full story).
Rechargeables are their own family: CTL and ML cells (solar G-Shocks and kinetic watches) share sizes with CR cells but not chemistry — never cross them (solar guide).
Not sure which cell your watch takes? Our battery finder answers from the model number.
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