A4 is the most frequently utilized paper size in the world. It is used as a classic sheet of paper in almost all industrialized countries, except of North America, in the case of which local standards are followed. The total surface of A4 is equal to 0,062 square meters that is - 62 cm2. The dimensions of an A4 sheet of paper are 210 x 297. The surface of A4 expressed in pixels is 2480px x 3508px, and in points - 595,3pt x 841,9pt.
The ratio between A4 and A0, the biggest format normalized by the ISO 216 standard is 16 to 1, which means that a singular A0 sheet of paper consists of 16 A4 ones. The said principle can be applied while calculating the basis weight of a sheet of A4 paper, as its mass is provided in grams per square meter. In the case of A4, the most common basis weight is 80. The said number has to then be divided by 16, as A0 consists of 16 A4 sheets of paper. Thanks to the said formula, one is capable of calculating the mass of a singular piece of paper. The size of A4 is equal to the half of an A3 sheet of paper.