ISO Paper sizes
In the ISO paper size system, the height-to-width ratio of all pages is the square root of two (1.4142 : 1). In other words, the width and the height of a page relate to each other like the side and the diagonal of a square. This aspect ratio is especially convenient for a paper size. If you put two such pages next to each other, or equivalently cut one parallel to its shorter side into two equal pieces, then the resulting page will have again the same width/height ratio.
The ISO paper sizes are based on the metric system. The square-root-of-two ratio does not permit both the height and width of the pages to be nicely rounded metric lengths. Therefore, the area of the pages has been defined to have round metric values. As paper is usually specified in g/m≤, this simplifies calculation of the mass of a document if the format and number of pages are known.
ISO Sizes A series
| ISO Code | Size in millimeters | Size in inches | Size in Points |
|---|---|---|---|
| 4A0 | 1682 mm x 2378 mm | 66.22 in x 93.62 in | 4768 pt x 6741 pt |
| 2A0 | 1189 mm x 1682 mm | 46.81 in x 66.22 in | 3370 pt x 4768 pt |
| A0 | 841 mm x 1189 mm | 33 in x 46.81 in | 2384 pt x 3370 pt |
| A1 | 594 mm x 841 mm | 23.39 in x 33 in | 1684 pt x 2384 pt |
| A2 | 420 mm x 594 mm | 16.54 in x 23.36 in | 1191 pt x 1684 pt |
| A3 | 297 mm x 420 mm | 11.69 in x 16.54 in | 842 pt x 1191 pt |
| A4 | 210 mm 297 mm | 8.27 in x 11.69 in | 595 pt x 842 pt |
| A5 | 148 mm x 210 mm | 5.83 in x 8.27 in | 420 pt x 595 pt |
| A6 | 105 mm x 148 mm | 4.13 in x 5.83 in | 298 pt x 420 pt |
| A7 | 74 mm x 105 mm | 2.91 in x 4.13 in | 210 pt x 298 pt |
| A8 | 52 mm x 74 mm | 2.05 in x 2.91 in | 147 pt x 210 pt |
| A9 | 37 mm x 52 mm | 1.46 in x 2.05 in | 105 pt x 147 pt |
| A10 | 26 mm x 37 mm | 1.02 in x 1.46 in | 74 pt x 105 pt |
The B series formats are geometric means between the A series format with the same number and the A series format with one lower number. For example, B1 is a geometric mean between A1 and A0. The sides of B0 are 1 m to v2 m.
ISO Sizes B series
| ISO Code | Size in millimeters | Size in inches | Size in Points |
|---|---|---|---|
| B0 | 1000 mm x 1414 mm | 33.37 in x 55.67 in | 2836 pt x 4008 pt |
| B1 | 707 mm x 1000 mm | 27.84 in x 39.37 in | 2004 pt x 2835 pt |
| B2 | 500 mm x 707 mm | 19.69 in x 27.84 in | 1417 pt x 2004 pt |
| B3 | 353 mm x 500 mm | 13.9 in x 19.69 in | 1001 pt x 1417 pt |
| B4 | 250 mm x 352 mm | 9.84 in x 13.9 in | 709 pt x 1001 pt |
| B5 | 176 mm x 250 mm | 6.93 in x 9.84 in | 499 pt x 709 pt |
| B6 | 125 mm x 176 mm | 4.92 in x 6.93 in | 354 pt x 499 pt |
| B7 | 88 mm x 125 mm | 3.47 in x 4.92 in | 249 pt x 354 pt |
| B8 | 62 mm x 88 mm | 2.44 in x 3.47 in | 176 pt x 249 pt |
| B9 | 44 mm x 62 mm | 1.73 in x 2.44 in | 125 pt x 176 pt |
| B10 | 31 mm x 44 mm | 1.22 in x 1.73 in | 88 pt x 125 pt |
ISO size variations
The following sizes are all variations on paper sizes in the ISO series. Since these are european standards, the size in inches is aproxiamte.
| Name | Size in millimeters | Size in inches |
|---|---|---|
| A2 extra | 445 mm x 619 mm | 17.51 in x 24.3 in |
| A3 extra | 322 mm x 445 mm | 12.67 in x 17.51 in |
| A3 Super | 305 mm x 508 mm | 12 in x 20 in |
| Super A3 | 305 mm x 487 mm | 12 in x 19.17 in |
| A4 extra | 235 mm x 322 mm | 9.25 in x 12.67 in |
| A4 Super | 229 mm x 322 mm | 9.25 in x 12.67 in |
| Super A4 | 227 mm x 356 mm | 8.93 in x 14.01 in |
| A4 Long | 210 mm x 348 mm | 8.26 in x 13.7 in |
| A5 extra | 173 mm x 235 mm | 8.26 in x 9.25 in |
| SO B5 extra | 202 mm x 276 mm | 7.95 in x 10.86 in |
The current ISO 216 standard was introduced in 1975 and is a direct follow up to the german DIN 476 standard from 1922. The Netherlands have used the DIN/ISO standard since 1925, Belgium since 1924, England (UK) since 1959 and France since 1967. ISO 216 is also called EN 20216 in Europe.
For the ISO C series please refer to our over view of ISO Envelope sizes.