A simple, free, comprehensive resource for finding the international standards for paper sizes in metric and imperial. Find the dimensions and formats of A4 paper and other paper sizes in different standards and regions. Compare A4 with other paper sizes in mm, inches, centimeters and more. Whether you’re printing documents, certificates, or reports, understanding A4 paper size and GSM helps you pick the right paper for your needs. Here's a complete guide on dimensions and use-cases. A4 size is one of the paper sizes in the ISO A series, which was defined by ISO216 and first put forward by German scientist Georg Christoph Lichtenberg as DIN476 standard of Germany and later adopted by ISO. Under the same standard, there is also B size series, which follows the same rule as A series: ratio of length to width of a piece of paper should be √2:1. A4 is the most well-known and widely used paper size in the A-series format. It is the standard size for most printed documents ...
