A Guide to paper size

by Michael Archer on April 26, 2023

Here at UK Card Crafts, you will find many different paper sizes. All of our paper products conform to the paper dimensions set by the International Standards Organisation (ISO). These standards, which are based on metric measurements, were adopted by the British Standards Institution in 1959 and are used in many countries across the globe.
There are three main series of size standards for paper: the A series, the B series and the C series. However, we shall concentrate on the A sizes for now.


The A Series

The A series starts at A0, which is the biggest size, and goes up to A10, which is the smallest size. A0 comprises a one square metre rectangle of paper measuring 1189 millimetres in height by 841 millimetres in width. All of the A sizes of paper derive from this starting point, allowing all of the sizes to be measured on the basis of grams per square metre.

The proportion between the two sides of a sheet of paper in the A series is the square root of 2 or 1:1.4142. This 1:1.4142 ratio permits all of the sheets in the A series to be exact multiples of the sheet sizes above and below them. For example, if you cut an A0 sheet in half, you would create two A1 sheets. Within the A series, the most common paper sizes used in crafts are A5, A4 and A3.


The A Series Sizes (measured in height x width)

A0 1189 mm x 841 mm (46.8 in x 33.1 in)
A1 841 mm x 594 mm (33.1 in x 23.4 in)
A2 594 mm x 420 mm (23.4 in x 16.5 in)
A3 420 mm x 297 mm (16.5 in x 11.7 in)
A4 297 mm x 210 mm (11.7 in x 8.3 in)
A5 210 mm x 148 mm (8.3 in x 5.8 in)
A6 148 mm x 105 mm (5.8 in x 4.1 in)
A7 105 mm x 74 mm (4.1 in x 2.9 in)
A8 74 mm x 52 mm (2.9 in x 2.0 in)
A9 52 mm x 37 mm (2.0 in x 1.5 in)
A10 37 mm x 26 mm (1.5 in x 1.0 in)