Poster sizes in general stick to ISO paper standard sizes. Litho and screen printers need to use these standard sizes to print onto a fixed sheet size.
It’s also wise to stick these standards in large format digital print, as although they print onto a roll rather than sheets, most poster frames, billboards, pavement signs etc come in these set sizes.
ISO paper sizes
| Format | A series | B series | C series |
|---|---|---|---|
| Size | mm × mm | mm × mm | mm × mm |
| 00 | 1189 x 1682 | – | – |
| 0 | 841 × 1189 | 1000 × 1414 | 917 × 1297 |
| 1 | 594 × 841 | 707 × 1000 | 648 × 917 |
| 2 | 420 × 594 | 500 × 707 | 458 × 648 |
| 3 | 297 × 420 | 353 × 500 | 324 × 458 |
| 4 | 210 × 297 | 250 × 353 | 229 × 324 |
In the UK we also still use some standard imperial sizes for posters, such as 40″x30″ and 60″x40″.
Imperial paper sizes
| Size | inch × inch | mm × mm |
|---|---|---|
| 60×40 | 60 x 40 | 1016 x 1524 |
| 40×30 | 40 x 30 | 762 x 1016 |
| 30×20 | 30 x 20 | 508 x 762 |
Visual reference
(Click to enlarge)