Where does this come from, and can I check it?

The letters are legacy size labels, and AA is much larger than AAA. The figure is taken from International Electrotechnical Commission, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a everyday life fact?

Yes. It sits on the Everyday Life shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

AA and AAA battery names are not measurements

The letters are legacy size labels, and AA is much larger than AAA Letters such as AA, AAA, C and D are historical size designations, and the international code adds the chemistry: an alkaline AA is LR6 and a zinc carbon one is R6. An AA cell is 14.5 millimetres wide and 50.5 millimetres tall, while an AAA is 10.5 by 44.5 millimetres. Only the codes, not the familiar letters, carry the full specification. It sits in Mondo's everyday life collection, one of 200 facts that each trace back to the reference below.

Where this comes from

International Electrotechnical Commission

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Tags: batteries, standards, electronics

AA and AAA battery names are not measurements: the short answers

Where does this come from, and can I check it?: The letters are legacy size labels, and AA is much larger than AAA. The figure is taken from International Electrotechnical Commission, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a everyday life fact?: Yes. It sits on the Everyday Life shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.