====== Standard A Paper Sizes (ISO 216) ======

The **A series paper sizes** are defined by the **ISO 216** international standard. They are widely used around the world for general printing, office, and publishing purposes (except in North America).

===== Key Features =====
  * The aspect ratio of all A series paper sizes is **1:√2** (approximately 1:1.414).
  * Cutting an A-size sheet in half *parallel to its shorter side* gives the next smaller A size (e.g., cutting A4 in half gives two A5 sheets).
  * The base size is **A0**, which has an area of **1 square meter**.

{{ :images:a_size_illustration2.png |}}

===== A Series Sizes (Dimensions in mm and inches) =====

^ Size ^ Dimensions (mm) ^ Dimensions (in) ^ Common Uses ^
| A0 | 841 × 1189 | 33.1 × 46.8 | Posters, architectural drawings |
| A1 | 594 × 841  | 23.4 × 33.1 | Technical drawings, flipcharts |
| A2 | 420 × 594  | 16.5 × 23.4 | Medium-sized posters, diagrams |
| A3 | 297 × 420  | 11.7 × 16.5 | Booklets, tabloid-sized documents |
| A4 | 210 × 297  | 8.3 × 11.7  | Letters, reports, office printing |
| A5 | 148 × 210  | 5.8 × 8.3   | Notebooks, flyers, small booklets |
| A6 | 105 × 148  | 4.1 × 5.8   | Postcards, small invitations |
| A7 | 74 × 105   | 2.9 × 4.1   | Pocket-size notes, tickets |
| A8 | 52 × 74    | 2.0 × 2.9   | Business cards, small labels |
| A9 | 37 × 52    | 1.5 × 2.0   | Coupons, tiny labels |
| A10| 26 × 37    | 1.0 × 1.5   | Microprint, stamps |

===== Quick Facts =====
  * **A4** is the most commonly used size for documents and letters.
  * All sizes maintain the same proportions, so content can scale without changing layout.
  * These sizes are especially useful for layout planning and print design workflows.

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