Capacity — 150–200 mAh vs 150–175 mAh
Typical 357 capacity is 150–200 mAh. 303 is 150–175 mAh. Runtime only follows that gap inside the correct holder. Extra capacity in the wrong tray does not last longer — it often does not run at all.
Sometimes — check chemistry/fit
357 vs 303
357 vs 303 Watch Battery
Both are SR44-family silver oxide cells (11.6 × 5.4 mm). 357 is typically the high-drain label; 303 is the low-drain counterpart on many watch charts.
Last verified Aug 25, 2026
Are 357 and 303 interchangeable?
Often interchangeable in watches; consult your movement manual for drain type.
Fit can look fine while chemistry, drain class, or temperature rating is still wrong. Use the stamp on the old cell, then the rows that differ in the spec table — not the fact that both cells are round.
357 vs 303 specs: capacity
They share 1.55 V and SilverOxide and 11.6 mm diameter, which is why 357 vs 303 looks interchangeable on a store shelf. Highlighted rows are the ones that change the purchase: capacity.
Read physical fit before capacity. Extra milliamp-hours only help when the holder is built for that cell. A “better” spec in the wrong tray is a mechanical or voltage mismatch, not an upgrade.
Difference between 357 and 303 batteries
If you searched 303 vs 357, you are on the same comparison with the names reversed. The difference between 357 and 303 batteries is not the word “vs” — it is the specs that do not match after you ignore the similar photos.
Same size and silver oxide chemistry family
Same size and silver oxide chemistry family
357 ≈ high-drain; 303 ≈ low-drain on many manufacturer charts
357 ≈ high-drain; 303 ≈ low-drain on many manufacturer charts
Chronographs and light modules may specify high-drain
Chronographs and light modules may specify high-drain
Simple quartz movements often accept either
Simple quartz movements often accept either
How the size code works (357 vs 303)
Coin and button codes are rulers, not brand slogans. The letters mark chemistry class. The digits encode size. 357 measures 11.6 × 5.4 mm; 303 measures 11.6 × 5.4 mm. Once you read the code that way, 303 vs 357 stops looking like a preference and starts looking like a fit check.
Can I use a 357 instead of a 303?
Sometimes. 357 may physically sit where 303 sat, but chemistry or drain class can still be wrong. Watches, meters, and charged circuits are where “it fits” is not enough.
If the door closes without force and the device asks for this chemistry, a quality 357 can work. If the datasheet named 303 for a reason — temperature, drain, or charge control — keep that code.
Can I use a 303 instead of a 357?
The same “sometimes” applies with the names reversed. Confirm chemistry and the movement or board chart, not just whether the can drops in.
A cheaper substitute that sags under load will look fine for a week and then make a watch run slow or a meter drift.
How to identify 357 versus 303
You do not need a full datasheet to settle 357 vs 303. You need the stamp, the tray, or a cheap pair of calipers. A store bin labeled only “button cell” or “3V lithium” will not do that work for you.
- Read the code on the old cell: 357, 303, and the brand prefixes that map to each one.
- If the print is worn off, check the tray, battery door, or user manual before buying.
- Measure diameter if the codes are gone: 357 is 11.6 mm; 303 is 11.6 mm.
- Measure thickness: 357 is 5.4 mm; 303 is 5.4 mm.
- Buy the matching code. Extra capacity or a thicker can only helps when the holder is built for that cell.
Choose 357 when…
- Movement chart or old cell says 357 / SR44W
Choose 303 when…
- Chart says 303 / SR44SW for low-drain
Compatibility and substitution
When in doubt, match the number on the movement chart. Size compatibility is excellent; drain labeling is the nuance.
Do not stack cells, grind a can, or use foil as a permanent spacer to fake 303 with 357. Read the stamp, then the spec table. If the door will not close without force, you have the wrong height or diameter.
357 vs 303 FAQ
Can I put 357 in a 303 watch?
Often yes. If the watch has unusual power features, prefer the exact drain type listed.
I searched 303 vs 357 — is this the right page?
Yes. 357 vs 303 and 303 vs 357 are the same pair. Fit, voltage, and chemistry do not change when you flip the order.
Should I always trust a cross-reference chart?
Use this guide as a starting point, then confirm voltage, chemistry, and physical size with your device manual or the marking on the old cell.
Review record and primary sources
Reviewed by PlainBattery Technical Review Desk on 2026-08-25. Checked: both model identities and dimensions, voltage and chemistry differences, physical fit, interchangeability conclusion and safety warnings.
- Silver Oxide (SR) and Alkaline Button (LR) Battery Specifications — Maxell. SR/LR model dimensions, voltage, nominal capacity and drain class.
- Energizer 357/303 / IEC SR44 Product Datasheet — Energizer Holdings, EBC-4349C. SR44/357/303 dimensions, chemistry, voltage and low-drain performance.
Revision record: source citations and field-level review scope added September 11, 2026. See our sources and methodology and corrections policy.