ISO 216

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ISO 216 sizes
(mm × mm)
A Series
A0 841 × 1189
A1 594 × 841
A2 420 × 594
A3 297 × 420
A4 210 × 297
A5 148 × 210
A6 105 × 148
A7 74 × 105
A8 52 × 74
A9 37 × 52
A10 26 × 37
B Series
B0 1000 × 1414
B1 707 × 1000
B2 500 × 707
B3 353 × 500
B4 250 × 353
B5 176 × 250
B6 125 × 176
B7 88 × 125
B8 62 × 88
B9 44 × 62
B10 31 × 44
C Series
C0 917 × 1297
C1 648 × 917
C2 458 × 648
C3 324 × 458
C4 229 × 324
C5 162 × 229
C6 114 × 162
C7/6 81 × 162
C7 81 × 114
C8 57 × 81
C9 40 × 57
C10 28 × 40
DL 110 × 220

ISO 216 specifies international standard (ISO) paper sizes, used in most countries in the world today. It is the standard which defines the well-known A4 paper size.

The standard was originally adopted by DIN (as DIN 476) in Germany in 1922, although some of the formats contained therein were independently invented in France during its revolution and later forgotten. [1] The aspect ratio used by this norm was already mentioned in a letter by the German Georg Christoph Lichtenberg written 1786-10-25. [2]

ISO 216 defines two series of paper sizes: A and B. There is also a C series for envelopes, defined in ISO 269.

Contents

[edit] A series

Paper in the A series format has a 1:\sqrt{2} aspect ratio, though this is rounded to the nearest millimetre. A0 is defined so that it has an area of 1 , prior to the above mentioned rounding. Successive paper sizes in the series A1, A2, A3, etc., are defined by halving the preceding paper size parallel to its shorter side, again prior to rounding. The most frequently used paper size is A4 (210 × 297 mm).

[edit] B series

The B series formats are geometric means between the A series format with the same number and the A series format with one lower number. For example, B1 is a geometric mean between A1 and A0. The sides of B0 are 1 m to \sqrt{2} m.

There is also an incompatible Japanese B series defined by the JIS. The lengths of JIS B series paper are approximately 1.22 times those of A-series paper.

[edit] C series

The C series formats are geometric means between the B series format with the same number and the A series format with the same number, e.g. C2 is the geometric mean between B2 and A2. The C series formats are used mainly for envelopes. An A4 page will fit into a C4 envelope. If you fold the A4 page so that it is A5 in size, it will fit in a C5 envelope and so on.

[edit] Tolerances

The tolerances specified in the standard are

  • ±1.5 mm for dimensions up to 150 mm,
  • ±2 mm for lengths in the range 150 to 600 mm, and
  • ±3 mm for any dimension above 600 mm.

[edit] A, B, C comparison

ISO/DIN paper sizes in millimetres and in inches
A Series Formats B Series Formats C Series Formats
size mm inches mm inches mm inches
0 841 × 1189 33.1 × 46.8 1000 × 1414 39.4 × 55.7 917 × 1297 36.1 × 51.1
1 594 × 841 23.4 × 33.1 707 × 1000 27.8 × 39.4 648 × 917 25.5 × 36.1
2 420 × 594 16.5 × 23.4 500 × 707 19.7 × 27.8 458 × 648 18.0 × 25.5
3 297 × 420 11.7 × 16.5 353 × 500 13.9 × 19.7 324 × 458 12.8 × 18.0
4 210 × 297 8.3 × 11.7 250 × 353 9.8 × 13.9 229 × 324 9.0 × 12.8
5 148 × 210 5.8 × 8.3 176 × 250 6.9 × 9.8 162 × 229 6.4 × 9.0
6 105 × 148 4.1 × 5.8 125 × 176 4.9 × 6.9 114 × 162 4.5 × 6.4
7 74 × 105 2.9 × 4.1 88 × 125 3.5 × 4.9 81 × 114 3.2 × 4.5
8 52 × 74 2.0 × 2.9 62 × 88 2.4 × 3.5 57 × 81 2.2 × 3.2
9 37 × 52 1.5 × 2.0 44 × 62 1.7 × 2.4 40 × 57 1.6 × 2.2
10 26 × 37 1.0 × 1.5 31 × 44 1.2 × 1.7 28 × 40 1.1 × 1.6
ISO A series
Enlarge
ISO A series
ISO B series
Enlarge
ISO B series

[edit] Application

Prior to the adoption of ISO 216, many different paper formats were used internationally. These formats did not fit into a coherent system and were defined in terms of non-metric units. The ISO 216 formats are organized around the ratio 1:\sqrt{2}; two sheets next to each other together have the same ratio, sideways. This simplifies copying two A4 sheets in reduced size on one, and copying an A4 sheet in magnified size on an A3 sheet or copying half an A4 sheet in magnified size on an A4 sheet. The principal countries not generally using the ISO paper sizes are the United States of America and Canada, which use the Letter, Legal, and Executive system. (Canada uses a P-series of sizes, which are the American paper sizes rounded to metric dimensions.)

Rectangular sheets of paper with the ratio 1:\sqrt{2} are popular in paper folding, where they are sometimes called "A4 rectangles" or "silver rectangles".[3] (Confusingly, "silver rectangle" can also refer to a rectangle in the proportion 1:(1+\sqrt{2}), known as the silver ratio.)

[edit] External links