WHAT IS DESIGN FOR PRINT?//PAPER FORMATS/SERIES A//OUGD504

PAPER FORMATS/SERIES A:
The dimensions of the A series paper sizes, as defined by ISO 216, are given in the table below in both millimetres and inches (cm measurements can be obtained by dividing mm value by 10). The A Series paper size chart to the right gives a visual explanation of how the sizes relate to each other - for example A5 is half of A4 size paper and A2 is half of A1 size paper.

TABLE OF PAPER SIZES FROM 4A0 TO A10:

To obtain paper sizes in centimetres, convert mm values to cm by dividing by 10 and in feet by dividing inch values by 12.

The paper sizes bigger than A0, 4A0 & 2A0, aren't formerly defined by ISO 216 but are commonly used for oversized paper. The origin of these formats is in the German DIN 476 standard, that was the original base document from which ISO 216 was derived.

A SERIES PAPER SIZE TOLERANCES:

ISO 216 specifies tolerances for the production of A series paper sizes as follows:

• ±1.5 mm (0.06 in) for dimensions up to 150 mm (5.9 in)
• ±2 mm (0.08 in) for lengths in the range 150 to 600 mm (5.9 to 23.6 in)
• ±3 mm (0.12 in) for any dimension above 600 mm (23.6 in)

A SERIES PAPER SIZES DEFINED:

The A series paper sizes are defined in ISO 216 by the following requirements:

• The length divided by the width is 1.4142
• The A0 size has an area of 1 square metre.
• Each subsequent size A(n) is defined as A(n-1) cut in half parallel to its shorter sides.
• The standard length and width of each size is rounded to the nearest millimetre.

Note: For reference the last item is there because the root 2 aspect ratio doesn't always give a whole number.

http://www.papersizes.org/a-paper-sizes.htm