Areas Of A Series Paper Sizes

A Paper Size Areas - Quick Lookup

Select the standard paper size from the 'Size' selector and the unit from the 'Unit' selector - the area will be shown in the area box.

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The area of each of the A paper sizes are set by the A paper size definitions (see below). A0 is defined as having an area of 1 square metre, however the A paper size standard also specifies that each size is rounded to the nearest millimetre. Thus A0 is 841mm x 1189mm giving an area of 0.999949 square metres.

Theoretically the area of a sheet of paper of size An can be calculated as 1/2n m2.

The following table gives theoretical areas compared with actual areas for each of the A paper sizes from 4A0 to A10.

Table of Theoretical and Actual Areas of A Paper Sizes

SizeTheoretical Area (sq m)Actual Area (sq m)Difference (sq m)Difference (%)

At the smaller sizes (A8, A9 & A10) the discrepancy between the theoretical area of the sheet and the actual area is about 1.5%. Larger sizes have significantly lower differences between the theoretical area and the actual area.

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.