Paper size

There have been many standard sizes of paper at different times and in different countries.

The international standard is ISO 216, which defines amongst others, A4. ISO paper sizes are all based on a single aspect ratio of the square root of two, 1:1.4142. The largest standard size, A0, has an area of 1 m². A1 is formed by cutting a piece of A0 in half, which retains the aspect ratio. This particular measurement system was chosen in order to allow folding of one standard size into another, which cannot be accomplished with traditional paper sizes.

The ISO B series is a scaling of the A series, B1 is half way between A0 and A1 in size. The C series is half way between the A and B series of the same number, for instance, C0 is half way between A0 and B0. This way C0 is slightly larger than A0, and B0 slightly larger than C0. This was intended to allow one to fit inside an envelope of the other. For instance, a letter written on A4 paper, the standard for this role, fits inside a C4 envelope. A C4 envelope can fit inside a B4 envelope.

ISO 216 does not define any sizes larger than A0 and B0, but the German standard DIN 476 puts a factor in front of these (so 2A0 is twice the size of A0, 4A0 is four time A0, etc.).

International standard paper sizes are now used in all countries except the United States, Canada, and some Latin American countries.

Table of contents

1 International Paper Sizes 2 US Paper Sizes 2..1 See also 3 External Link

International Paper Sizes

US Paper Sizes

See also

• Folio (paper size)

• International Standard Paper Sizes by