Paper and Card

The sizes of paper and card commonly used follow the ISO Standard - e.g. A4, A3 etc plus B4, C5 etc. There is also a North America Standard with sizes including letter, legal, ledger, etc.

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Note: The ratio of one side of ISO Standard paper to the other is √2 resulting in paper sizes which can be folded in half to create the next size.

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The most frequently used paper size is A4. A sheet measures 210 by 297 millimetres (8.27in × 11.7in) and a sheet of ordinary copier paper weighs 5 grams. Other common sizes are:

• A5 = 148mm × 210mm
• A3 = 297mm × 420mm
• A2 = 420mm × 594mm

The base A0 size of paper is defined as having an area of 1m² rounded to the nearest millimetre