The ISO follows the common rounding practice is to discarding any fraction of a millimeter. For instance, 840.9 mm becomes 840 mm and 324.2 mm becomes 324 mm.
One inch equals 25.4 millimeters.
| Designation | Dimensions in Millimeters |
|---|---|
| 4A0 | 2378 x 1682 |
| 2A0 | 1682 x 1189 |
| B0 | 1414 x 1000 |
| C0 | 1297 x 917 |
| A0 | 1189 x 840 |
| B1 | 1000 x 707 |
| C1 | 917 x 648 |
| A1 | 840 x 594 |
| B2 | 707 x 500 |
| C2 | 648 x 458 |
| A2 | 594 x 420 |
| B3 | 500 x 353 |
| C3 | 458 x 324 |
| A3 | 420 x 297 |
| B4 | 353 x 250 |
| C4 | 324 x 229 |
| A4 | 297 x 210 |
| B5 | 250 x 176 |
| C5 | 229 x 162 |
| A5 | 210 x 148 |
| B6 | 176 x 125 |
| C6 | 162 x 114 |
| A6 | 148 x 105 |
| B7 | 125 x 88 |
| C7 | 114 x 81 |
| A7 | 105 x 74 |
| B8 | 88 x 62 |
| C8 | 81 x 57 |
| A8 | 74 x 52 |
| B9 | 62 x 44 |
| C9 | 57 x 40 |
| A9 | 52 x 37 |
| B10 | 44 x 31 |
| C10 | 40 x 28 |
| A10 | 37 x 26 |