A Paper size calculator

a paper introduction

The most commonly used international standard for paper sizes is the ISO standard, adopted in 1922, which assigns sizes to numbers such as A4, B5, etc. The A series is the most commonly used. The width and length of 841 mm and 1189 mm (length to width ratio of 2 square root: 1), and numbered A0.
If the long side of the A0 paper is cut into two, you get two sheets of A1 paper, the width and length of 594 mm and 841 mm. In this way continue to cut the A1 paper, you can sequentially get A2, A3, A4 and other paper sizes.