ConverterHub

Battery Size Lookup

Enter a battery code to see its voltage, size, and chemistry.

How it is calculated

This is a table lookup, not a calculation. The text you enter is trimmed and upper-cased, so "cr2032" and " CR2032 " are the same, and then matched against a built-in list of 11 codes: AA, AAA, C, D, 9V, CR2032, CR2025, 18650, AG13, LR44 and 23A. Six alternative names are mapped to them: LR6 to AA, LR03 to AAA, LR14 to C, LR20 to D, and A23 or MN21 to 23A. A match returns the nominal voltage, the outer dimensions in millimetres (diameter × height for round cells, width × depth × height for the 9V) and the usual chemistry. Anything not in the list, including CR2016, CR123A, AAAA, or a code with a space such as "9 V", returns no result rather than a guess.

Worked example

Type CR2032. The tool finds it in the list and returns a nominal voltage of 3 V, dimensions of 20 × 3.2 mm (20 mm across, 3.2 mm thick) and the chemistry "Lithium (coin)". Compare with CR2025, which has the same 3 V and the same 20 mm diameter but is 2.5 mm thick, so it is 0.7 mm thinner. That one-digit difference in the code is why a thinner cell may rattle in a holder made for a CR2032.

Try this example →

Common mistakes

  • Typing a code with a space or dash, such as "9 V" or "CR-2032". The match is exact apart from case and outer spaces, so use 9V and CR2032.
  • Assuming a missing code means the battery does not exist. The list is short (11 codes and 6 aliases), so CR123A, CR2016 and AAAA simply are not covered.
  • Treating the voltage as what a rechargeable cell delivers in use. The value is the nominal figure for the listed chemistry: for AA and AAA the entry says Alkaline / NiMH, but a NiMH cell usually delivers about 1.2 V.
  • Swapping a button cell for a different code with similar size. LR44 and AG13 are the same entry here, but a CR2025 is not a substitute for a CR2032 despite the same diameter.
  • Reading the 9V dimensions as diameter × height. It is three numbers: width × depth × height of a rectangular block.

About this calculator

Common battery names like AA, 9V, CR2032, and 18650 are shorthand for standardized codes set by bodies such as IEC and ANSI, each specifying a fixed physical size, nominal voltage, and typical chemistry. An AA cell, for instance, is always about 14.5 mm by 50.5 mm regardless of brand, while a CR2032 is a 20 mm-diameter, 3.2 mm-thick lithium coin cell at 3 volts — the codes exist precisely so any compatible battery fits any device designed for that size.

This lookup tool matches a battery code to its voltage, dimensions, and common chemistry (alkaline, lithium, NiMH, and so on) in one step. It's a handy reference for electronics hobbyists, repair technicians, and anyone replacing a battery in a device like a watch, remote, camera, or flashlight, where picking the wrong physical size or voltage can mean a battery that simply doesn't fit or under/overpowers the device.

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