Paper & board sizes

In the ISO paper size system, all pages have a height-to-width ratio of the square root of two (1:1.4142).

This aspect ratio is especially convenient for paper size. If you put two pages with this aspect ratio next to each other, or equivalently cut one parallel to its shorter side into two equal pieces, then the resulting page will again have the same width/height ratio.

The ISO paper size concept

The ISO paper sizes are based on the metric system. The square-root-of-two ratio does not allow the height and width of the pages to be nicely rounded metric lengths. Therefore, the area of the pages has been defined to have nice metric values. As paper is usually specified in g/m², this allows easy calculation of the mass of a document if the format and number of pages are known.

Sheet size A0 has an area of 1 m².
The ratio of the sides of A and B series papers is 1:2.

A Series - for all printing work

Sheet SizeMillimetres
4A0 1682 x 2378
2A0 1189 x 1682
A0 841 x 1189
A1 594 x 841
A2 420 x 594
A3 297 x 420
A4 210 x 297
A5 148 x 210
A6 105 x 148
A7 74 x 105
A8 52 x 74
A9 37 x 52
A10 26 x 37

B Series - for posters, wall charts, etc

Sheet SizeMillimetres
B0 1000 x 1414
B1 707 x 1000
B2 500 x 707
B3 353 x 500
B4 250 x 353
B5 176 x 250
B6 125 x 176
B7 88 x 125
B8 62 x 88
B9 44 x 62
B10 31 x 44

C Series - for envelopes or folders to take A series items

Sheet SizeMillimetres
C0 917 x 1297
C1 648 x 917
C2 458 x 648
C3 324 x 458
C4 229 x 324
C5 162 x 229
C6 114 x 162
C7 81 x 114
C8 57 x 81
C9 40 x 57
C10 28 x 40

Stock sizes - for normal trims

Sheet SizeMillimetres
RA0 860 x 1220
RA1 610 x 860
RA2 430 x 610
RA3 305 x 430
RA4 215 x 305

Stock sizes - for bleeds or extra trims

Sheet SizeMillimetres
SRA0 900 x 1280
SRA1 640 x 900
SRA2 450 x 640
SRA3 320 x 450
SRA4 225 x 320