What is A4 Paper?

A4 paper is the standard paper size used worldwide, with the exception of countries. A4 paper is about 8.27 inches by 11.69 inches (21 cm by 29.7 cm). This and other types of “A” paper sizes are based on a metric measurement system and established through international European standards.

Basis for Different Sizes

A4 paper and a-like sizes are based on metric dimensions. An A0 piece of paper, when spread flat, has apart of one square meter and is the largest dimension at 84.1 cm by 118.9 cm. A0 paper, cut in half, becomes size A1 at concerning 59.4 cm by 84.1 cm. A1 cut in half is A2, and so on throughout A6.
This produces paper with dissimilar sizes, but all with a 1:1.414 height-to-width part. European standards also wrap B paper sizes. B0 paper is a meter wide and 1.414 meters tall; B1 is B0 cut in semi, and so forth through B5.
The worth of this system for paper sizes is that every size is proportionately identical to the next. A4 paper, for example, is 21 cm by 29.7 cm, while A3 is 29.7 cm by 42 cm. If someone has text or images on a sheet of A4 paper and wants to increase it onto A3 paper, it can be done fairly easily without lose any of the content of the document. This amount, which uses the square root of two, or 1.414, is recognized as the Lichtenberg Ratio, named for the German physicist who initial noted its usefulness.

Size and Standardization

Paper sizes were consistent in Germany in 1922, and adopted during Europe in 1930, via Standard 216 of the International Standards Organization. The ISO is a non-governmental unit that publishes international values. While the standards have been efficient occasionally, the sizes used have been maintained since the early on 20th Century.

Paper Weight

The mass of European paper is based on the metric scheme and is standardized under ISO Standard 536, initially developed in 1976 and updated in 1995.