A quick post to help you check the dimensions of A, B, and C standard paper.

ISO 216 paper sizes are based on an aspect ratio of approximately 1:1.4142 – the square root of 2. The base format (A0) is a sheet spanning 1m² in area. Successive sheets in the series are made by halving the preceding paper size along the larger edge.

The advantage of this system lies in scaling: if a sheet with an aspect ratio of √2 is divided into two equal halves parallel to its shortest sides, then the halves will again have an aspect ratio of √2.

Developed from earlier ideas in Germany in 1922, the system quickly spread to other countries, and was established as an ISO standard in 1975.

The most frequently used of this series is A4. The US ‘Letter’ paper size – that you may frequently select by mistake in MS Word (as I do) – is 6mm wider and 18mm shorter than this.

Sheet | Dimensions (mm) |
---|---|

A0 | 1189 x 841 |

A1 | 841 x 594 |

A2 | 594 x 420 |

A3 | 420 x 297 |

A4 | 297 x 210 |

A5 | 210 x 148 |

A6 | 148 x 105 |

A7 | 105 x 74 |

A8 | 74 x 52 |

A9 | 52 x 37 |

A10 | 37 x 26 |

In less common use, the B Series is the geometric mean of successive A sheets. B sizes are usually found in poster design, books and envelopes.

Sheet | Dimensions (mm) |
---|---|

B0 | 1414 x 1000 |

B1 | 1000 x 707 |

B2 | 707 x 500 |

B3 | 500 x 353 |

B4 | 353 x 250 |

B5 | 250 x 176 |

B6 | 176 x 125 |

B7 | 125 x 88 |

B8 | 88 x 62 |

B9 | 62 x 44 |

B10 | 44 x 31 |

The C series is used only for envelopes. The area of C series sheets is the geometric mean of the areas of the A and B series sheets of the same number.

Sheet | Dimensions (mm) |
---|---|

C0 | 1297 x 917 |

C1 | 917 x 648 |

C2 | 648 x 458 |

C3 | 458 x 324 |

C4 | 324 x 229 |

C5 | 229 x 162 |

C6 | 162 x 114 |

C7 | 114 x 81 |

C8 | 81 x 57 |

C9 | 57 x 40 |

C10 | 40 x 28 |