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 size |
Millimetres |
| |
|
| 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 size |
Millimetres |
| |
|
| 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 size |
Millimetres |
| |
|
| 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 size |
Millimetres |
| |
|
| RAO |
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 size |
Millimetres |
| |
|
| SRA0 |
900 x 1280 |
| SRA1 |
640 x 900 |
| SRA2 |
450 x 640 |
| SRA3 |
320 x 450 |
| SRA4 |
225 x 320 |