page_title: Paper size
section_title: B series
hierarchical_section_title: Paper size / International paper sizes / B series
context_page_description: Paper size standards govern the size of sheets of paper used as writing paper, stationery, cards, and for some printed documents.
  The ISO 216 standard, which includes the commonly used A4 size, is the international standard for paper size. It is used across the world except in North America and parts of Central and South America, where North American paper sizes such as "Letter" and "Legal" are used. The international standard for envelopes is the C series of ISO 269.
context_section_description: The B series paper sizes are less common than the A series. They have the same aspect ratio of A series:
  However, they have a different area. The area of B series sheets is in fact the geometric mean of successive A series sheets. B1 is between A0 and A1 in size, with an area of 0.707 m² (​¹⁄√₂ m²). As a result, B0 is 1 metre wide, and other sizes of the series are a half, a quarter or further fractions of a metre wide: in general, every B size has one of its sides ​¹⁄power of two meters long. That side is the short side for B0, B2, B4, etc. and the long side for B1, B3, B5, etc.
  While less common in office use, the B series is used for a variety of special applications.
  Many posters use B-series paper or a close approximation, such as 50 cm × 70 cm ~ B2.
  B5 is a relatively common choice for books.
  B7 is equal to the passport size ID-3 from ISO/IEC 7810.
  B4, B5 and B6 are used for envelopes that fit C-series envelopes.
  The B-series is widely used in the printing industry to describe both paper sizes and printing press sizes, including digital presses. B3 paper is used to print two US letter or A4 pages side by side using imposition; four pages would be printed on B2, eight on B1, etc.
caption: A size chart illustrating the ISO B series.