### Paper Sizes

ISO paper dimensions provide a standardized international format based on metric dimensions. The basic size, A0, contains one square metre of paper, allowing all sizes to be commonly measured on the basis of grams per square metre. The weight of paper, expressed in grams per square metre (or gsm), provides an indication of it's thickness. For example, a sheet of 120gsm paper would be roughly double the thickness of a sheet of 60gsm paper.

There is no universal calculation for the thickness of paper based on the gsm as varitaions in paper composition can affect the weight, so two different brands of 120gsm paper could have slightly different thicknesses. However, an average sheet of 80gsm paper, the most commonly used weight, measures approximately 0.1mm in thickness, which means that 10 sheets would measure 1mm. By comparison, 10 sheets of 120gsm paper would be 1.5mm thick, assuming the paper composition was the same.

The proportion between the two sides of the sheet is specified as the square root of 2, or 1:1.4142. This ratio permits all sheets in the series to be an exact multiple of the sheet size above and below it. For example, A0 cut in half creates exactly two A1 sheets. The tables below show the dimensions for some of the most commonly used paper sizes:

## A series

The A series is the industry standard for the international metric market. Each size is exactly 1/2 the area of the previous size. The most common sizes for publication are A4 and A3 which folds in half to A4.

A series paper sizes
Size | Millimetres | Decimal Inches | Nearest 1/16" |

A0 |
841 x 1189 |
33.11 x 46.81 |
33 1/8 x 46 13/16 |

A1 |
594 x 841 |
23.39 x 33.11 |
23 3/8 x 33 1/8 |

A2 |
420 x 594 |
16.54 x 23.39 |
16 9/16 x 23 3/8 |

A3 |
297 x 420 |
11.69 x 16.54 |
11 11/16 x 16 9/16 |

A4 |
210 x 297 |
8.27 x 11.69 |
8 1/4 x 11 11/16 |

A5 |
148 x 210 |
5.83 x 8.27 |
5 13/16 x 8 1/4 |

A6 |
105 x 148 |
4.13 x 5.83 |
4 1/8 x 5 13/16 |

A7 |
74 x 105 |
2.91 x 4.13 |
2 15/16 x 4 1/8 |

A8 |
52 x 74 |
2.05 x 2.91 |
2 1/16 x 2 15/16 |

A9 |
37 x 52 |
1.46 x 2.05 |
1 7/16 x 2 1/16 |

A10 |
29 x 37 |
1.14 x 1.46 |
1 1/8 x 1 7/16 |

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## B series

The B series was designed to fill the voids between the A series sizes. These are used for special applications like posters, wall charts and labels.

B series paper sizes
Size | Millimetres | Decimal Inches | Nearest 1/16" |

B0 |
1000 x 1414 |
39.37 x 55.67 |
39 3/8 x 55 11/16 |

B1 |
707 x 1000 |
27.83 x 39.37 |
27 13/16 x 39 3/8 |

B2 |
500 x 707 |
19.69 x 27.83 |
19 11/16 x 27 13/16 |

B3 |
353 x 500 |
13.90 x 19.69 |
13 7/8 x 19 11/16 |

B4 |
250 x 353 |
9.84 x 13.90 |
9 13/16 x 13 7/8 |

B5 |
176 x 250 |
6.93 x 9.84 |
6 15/16 x 9 13/16 |

B6 |
125 x 176 |
4.92 x 6.93 |
4 15/16 x 6 15/16 |

B7 |
88 x 125 |
3.46 x 4.92 |
3 7/16 x 4 15/16 |

B8 |
62 x 88 |
2.44 x 3.46 |
2 7/16 x 3 7/16 |

B9 |
44 x 62 |
1.73 x 2.44 |
1 3/4 x 2 7/16 |

B10 |
31 x 44 |
1.22 x 1.73 |
1 1/4 x 1 3/4 |

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## C series

The C series is the standard series for envelopes and folders. Each C size envelope is designed to fit the corresponding A size flat sheet. For example, the C4 envelope is designed for the A4 letter. A special DL size envelope was designed to accommodate the traditional tri-folded letter.

C series paper sizes
Size | Millimetres | Decimal Inches | Nearest 1/16" |

C1 |
648 x 917 |
25.51 x 36.10 |
25 1/2 x 36 1/8 |

C2 |
458 x 648 |
18.03 x 25.51 |
18 x 25 1/2 |

C3 |
324 x 458 |
12.76 x 18.03 |
12 3/4 x 18 |

C4 |
229 x 324 |
9.02 x 12.76 |
9 x 12 3/4 |

C5 |
162 x 229 |
6.38 x 9.02 |
6 3/8 x 9 |

C6 |
114 x 162 |
4.49 x 6.38 |
4 1/2 x 6 3/8 |

DL |
110 x 220 |
4.33 x 8.66 |
4 5/16 x 8 11/16 |

by Andy Leighton