A5

A5 is a standard paper size defined by the ISO 216 standard as part of the A-series. It measures 210 millimeters by 148.5 millimeters (8.27 by 5.83 inches). It is obtained by halving A4 along its longer edge, preserving the same aspect ratio of 1:√2.

Common uses for A5 include notebooks, diaries, planners, brochures, leaflets, and small pamphlets. The format is widely available in printers and copiers, and is popular for personal and educational materials due to its portability and readability.

History and standardization: The A-series originates from the German DIN 476 standard introduced in 1922, and ISO 216 published in 1975 formalized its worldwide use. The dimensions are defined so that the area halves when moving to the next size.

Other uses: A5 may refer to other things, most notably the Audi A5, a line of luxury sport coupes and convertibles introduced in 2007, as well as various road designations in some countries.