7 min read
2026-02-08
The ISO 216 international standard defines the A series — the most common worldwide. The basis is an A0 sheet with an area of 1 m2. Each subsequent format is obtained by halving the previous one.
| Format | Size (mm) | Size (inches) | Use |
|---|---|---|---|
| A0 | 841x1189 | 33.1x46.8 | Blueprints, posters |
| A1 | 594x841 | 23.4x33.1 | Posters, diagrams |
| A2 | 420x594 | 16.5x23.4 | Posters |
| A3 | 297x420 | 11.7x16.5 | Blueprints, magazines |
| A4 | 210x297 | 8.3x11.7 | Documents, letters |
| A5 | 148x210 | 5.8x8.3 | Notebooks, books |
| A6 | 105x148 | 4.1x5.8 | Postcards |
| Format | Size (mm) | Size (inches) |
|---|---|---|
| Letter | 216x279 | 8.5x11 |
| Legal | 216x356 | 8.5x14 |
| Tabloid | 279x432 | 11x17 |
B Series — intermediate sizes between A series formats
C Series — used for envelopes (C4 fits an A4 sheet without folding)
Find the format you need in the Paper Size Reference.
See also: Screen Resolution, Cooking Measurement Converter