What are the Iso paper size standards?

ISO paper sizes are a set of international standards for paper sizes. They are defined in the ISO 216 standard, which was first published in 1975. The ISO 216 standard defines a series of paper sizes based on the aspect ratio of √2, which is approximately 1:1.414.

The most commonly used ISO paper sizes are:

- A4 (210 x 297 mm): This is the standard size for letters, documents, and other general office use in most of the world.

- A3 (297 x 420 mm): This size is often used for posters, brochures, and other large documents.

- A5 (148 x 210 mm): This size is commonly used for booklets, flyers, and postcards.

- A6 (105 x 148 mm): This size is often used for postcards, index cards, and other small documents.

- B4 (250 x 353 mm): This size is used for large envelopes and some technical drawings.

- C4 (229 x 324 mm): This size is used for envelopes that fit A4 paper.

In addition to the ISO 216 standard, there are also several other ISO paper size standards, including the ISO 269, ISO 276, and ISO 5457 standards. These standards define additional paper sizes that are used for specific purposes, such as engineering drawings, maps, and books.

ISO paper sizes are used in most countries around the world, with some exceptions. For example, in the United States and Canada, the most commonly used paper size is Letter, which is approximately 8.5 x 11 inches. However, ISO paper sizes are becoming increasingly popular in these countries as well.