Units of paper quantity Units of paper quantity Various measures of paper quantity have been and are in use. Although there are no S.I. units such as quires and bales, there are ISO and DIN standards for the ream. Expressions used here include U.S. Customary units. A quire of paper is a measure of paper quantity. The usual meaning is 25 sheets of the same size and quality: of a ream of 500 sheets. Quires of 25 sheets are often used for machine-made paper, while quires of 24 sheets are often used for handmade or specialised paper of 480-sheet reams. (As an old UK
Paper size containing less than 10 micrometers of paper The international paper size standard is ISO 216. It is based on the German DIN 476 standard for paper sizes. ISO paper sizes are all based on a single aspect ratio of the square root of 2, or approximately 1:1.4142. There are different series, as well as several extensions. The following international paper sizes are included in Cascading Style Sheets (CSS): "A3", "A4", "A5", "B4", "B5". The base A0 size of paper is defined as having an area of 1 m and a dimension ratio of 1 to , making the A0 paper