A1 ENVELOPE SIZE ISO
A1 ENVELOPE SIZE SERIES

For example, an A4 letter fits into C4 envelope, which in turn fits into a B4 envelope.

A1 ENVELOPE SIZE SERIES

Similarly, the sizes of the C series are the geometric mean between the A and B series formats with the same number. These percentages are demonstrated below when referring to photocopying machines. This percentage ration between sizes applies equally to both the height and width dimensions of each sheet size. So where A0 has a length of 1189mm, B1 will have a length of 1000mm and A1 will have a length of 841mm, each is approximately an 84.1% reduction of the larger size, or a 118.9% enlargement of the smaller size. In other words, the factor that scales A1 to B1 also scales B1 to A0. For instance, B1 is the geometric mean falling between A1 and A0. The width and height of a B series format is the geometric mean between the corresponding A format and the next larger A format. The C series of formats has been defined for envelopes.

A1 ENVELOPE SIZE ISO

Thus, A0 measure 841mm x 1189mm and A1 measures 594mm x 841mm, where 594mm is half the length of 1189mm and rounded down to the nearest millimetre.Īll smaller A series formats are defined in the same way by cutting the next larger format parallel to its shorter side into two equal halves, so A2 measures 420mm x 594mm, where 420mm is half of 841mm, rounded down.įor applications where the ISO A series does not provide an adequate range of sizes, the B series was created to provide a greater choice. The base format A0 (841mm x 1189mm) has an area of one square meter.Ī1 is A0 cut into two equal halves, where the A1 sheet long dimension is the same as the short dimension of A0 and the A1 short dimension is half the A0 long dimension. The height divided by the width of all formats is the square root of two (1.4142), hence, an A3 sheet is approximately 141% larger than an A4 sheet. ISO 216 defines the A series of paper sizes as follows: As the weight of paper in the metric system is specified in grams per square meter (gsm), a simple method of calculating the mass or weight of a publication is possible where the size and number of pages is known. The sizes, therefore are rounded to two whole millimetre lengths. The square-root-of-two ratio does not allow the height and width of pages to be given simple whole metric sizes. ISO paper sizes are based on the metric system. By placing two sheets of A series paper next to each other, or any cutting one in half, parallel to its shorter side, the resulting sheet will again have the same width to height ratio. With the ISO paper size system, all sheet sizes have a width to height ratio of the square root of two (1:1.4142). The following explains the ISO 216 paper size system and the principles.

The ISO A4 paper size is today commonly used throughout the world. Based on text by Markus Khun, lecturer with the University of Cambridge Computer Laboratory

A1 envelope size