Decode your coin cell
CR2032 is not a serial number: 20 is the diameter in millimetres, and 32 means 3.2 mm thick, at 3 V. Type the code on your cell to see what it says — and whether another cell can replace it.
CR2032: a 3 V lithium coin cell, ⌀ 20 mm × 3.2 mm, about 225 mAh. CR2025? Still 20 mm, but 2.5 mm — the lid may not close.
Decoder
CR2032
⌀ 20 × 3.2 mm · 3 V · 225 mAh typical · also 5004LC
CR: lithium · manganese dioxide · round
CR2025
⌀ 20 × 2.5 mm · 3 V · 160–165 mAh typical · also 5003LC
CR: lithium · manganese dioxide · round
CR2032 is thicker than CR2025 — the lid may not close. Not a good substitute.
Drawn to scale: heights and diameters stay proportional across cells.
CR2032 ⌀ 20 × 3.2 mm
The whole CR family at a glance
The 15 most common lithium coin cells, grouped by diameter. Capacities are typical datasheet values and vary between brands.
| Code | ⌀ (mm) | Height (mm) | mAh typical | Also known as |
|---|---|---|---|---|
| CR1025 | 10 | 2.5 | 30 | 5033LC |
| CR1216 | 12.5 | 1.6 | 25 | 5034LC |
| CR1220 | 12.5 | 2 | 35–40 | 5012LC |
| CR1225 | 12.5 | 2.5 | 50 | 5020LC |
| CR1616 | 16 | 1.6 | 50–55 | — |
| CR1620 | 16 | 2 | 75–78 | 5009LC |
| CR1632 | 16 | 3.2 | 140 | — |
| CR2016 | 20 | 1.6 | 90 | 5000LC |
| CR2025 | 20 | 2.5 | 160–165 | 5003LC |
| CR2032 | 20 | 3.2 | 225 | 5004LC |
| CR2320 | 23 | 2 | 110–175 | — |
| CR2330 | 23 | 3 | 265 | — |
| CR2354 | 23 | 5.4 | 560 | — |
| CR2430 | 24.5 | 3 | 270–290 | 5011LC |
| CR2450 | 24.5 | 5 | 610–620 | 5029LC |
How to read a code
The first letter names the chemistry — and with it the voltage: C is lithium manganese dioxide (3 V), B lithium carbon monofluoride (also 3 V), L alkaline (1.5 V), S silver oxide (1.55 V), P zinc-air (1.4 V). R simply means round.
The last two digits are the height in tenths of a millimetre — 32 means 3.2 mm — and the digits before are the diameter in millimetres, rounded down: that is why a CR1216 is really 12.5 mm. Wide five-digit codes read the same way (a CR11108 is 11.6 × 10.8 mm), while two-digit ones like LR44 are legacy numbers that encode no size.
Two pocket rules: never mix voltages — 3 V where 1.5 V belongs can damage the device — and at the same diameter the height must match: a thinner cell loses contact, a thicker one keeps the lid from closing. Lithium coin cells are not rechargeable, do not belong in household waste, and must stay away from small children.
Frequently asked questions
Can I replace a CR2025 with a CR2032?
No. Both are 20 mm across, but the CR2032 is 3.2 mm thick versus 2.5 mm for the CR2025: the holder lid may not close.
Can I stack two CR2016 instead of one CR2032?
No. Two CR2016 in series give 6 V instead of 3 V, even though the total 3.2 mm height fits. Double voltage can damage the device.
What is the difference between CR2032 and BR2032?
Same size (20 × 3.2 mm) and same 3 V; the chemistry differs: BR uses carbon monofluoride, with lower self-discharge. Usually interchangeable, but check the device manual.
Why does LR44 not decode the same way?
Because 44 is a legacy number that encodes no size. The LR44 is a 1.5 V alkaline cell, not a 3 V lithium one.
A new cell reads 3.6 V on my multimeter. Is it faulty?
No. 3 V is the nominal on-load voltage; unloaded, a new lithium coin cell reads about 3.6 V.
Sources and method
- Table sizes and capacities are from Wikipedia's list of battery sizes.
- The letter system, nominal voltages and digit rules follow the Button cell article, IEC 60086.
- Capacities are typical values and vary between manufacturers; the coded diameter is rounded down (12.5 mm appears as “12”).