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2 different reputable sources list 2 different A4 page dimensions: 8.27 x 11.69 and 8.27 x 11.7.

Furthermore, I have 2 different PDF resize programs. 1 outputs A4 files as 8.26 x 11.69, the other outputs files as 8.27 x 11.69.

Thus, among 2 different sources and 2 different programs, there are 3 different outputs for A4: 8.26 x 11.69, 8.27 x 11.69, and 8.27 x 11.7.

Why are there so many different outputs for A4, and which is actually the correct dimensions?

abcjme
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    The correct A4 dimension are: 210 mm × 297 mm . Everything you mentioned are approximations. –  Jan 29 '18 at 00:35
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    The problem is that you're using primitive imperial measurements, about as useful as furlongs per fortnight as a measure of speed. Get with the metric system :-) –  Jan 29 '18 at 05:56
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    Hi, abcjme welcome on SuperUser. Can you [edit] your question and add the reference to the _reputable sources_. Just to be more complete. – Hastur Jan 29 '18 at 09:05
  • Margins are assumed as well. Some printers have support for "wide A4" (HP), but absolutely no documentation for what this really means. – mckenzm Jan 29 '18 at 19:32
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    *8.27 x 11.69* what? and *8.27 x 11.7*? Furlongs? Potatoe-lengths? – Bakuriu Jan 29 '18 at 21:10
  • @Bakuriu - Freedom Units – BruceWayne Jan 29 '18 at 21:37
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    A difference of 0.01 Arbitrary Units is less than the manufacturing error of your typical sheet of paper. – Mark Jan 30 '18 at 00:00
  • @mckenzm the margins of a document is part of the contents in regards to printing and paper size, and thus shouldn't change the dimensions of the medium ;) – Flygenring Jan 30 '18 at 09:40
  • @paxdiablo Not me, the sources and programs. – abcjme Feb 04 '18 at 11:09

1 Answers1

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It is just because of rounding errors, due to how dimensions were computed, starting from A0, there are mathematical properties to define each subsequent format.

However the A4 standard says it is 210 mm × 297 mm with tolerances: ±2.0 mm for dimensions in the range 150 to 600 mm.

See the wikipedia entry: https://en.wikipedia.org/wiki/ISO_216#A_series

Now you seem to deal with inches (you did not say!), so 210mm is 8.26772 inches, which would round to 8.27 and 297mm is 11.69291 inches, hence 11.69 if rounded to two digits after the decimal. Of course that will be respectively 8.3 and 11.7 if you round to one digit only.

Patrick Mevzek
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    It's worth saying explicitly that all numbers in the question are valid as ISO 216 A4, as all are within tolerance. – Mołot Jan 29 '18 at 15:38
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    @Mołot Though how often do you see A4 paper that is even 1mm out? – curiousdannii Jan 29 '18 at 15:51
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    @curiousdannii Though how often do you measure A4 paper? – Digital Trauma Jan 30 '18 at 01:53
  • @DigitalTrauma - I regular place A4 sheets from different sources on stacks together, and would notice a difference of more than about 1/2mm on doing so. It's a rare occurrence that even this much error occurs (the only time I've ever seen it was a set of headed paper that was cut down from A3 sheets by the printer using a badly calibrated guillotine, leaving half the stack slightly too wide and half slightly too narrow). – Jules Jan 30 '18 at 09:45
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    @curiousdannii actually pretty often,when I'm using very cheap printing paper or when I'm using expensive one that only comes in A3 format and is cut in half in printing shop. Within tolerance = I can't file a compliant. – Mołot Jan 30 '18 at 10:55
  • @DigitalTrauma while I do almost never measure A4 paper I very often refill printers with papers from different manufacturers on top of older ones, and so far they seem to be perfectly the same size. – PlasmaHH Jan 30 '18 at 12:44