A Paper Sizes

Now most countries in the world are using same dimension standard of papers, and you can find the same size rule in any paper documents in these countries. This unified standard greatly improves the convenience of communication in political, cultural, legal and other aspects with paper documents between countries. In this regard, we should thank the scientist who put forward standard ideas and the industry experts who introduced ISO standard paper sizes to different countries (except North America, Mexico, the Philippines, etc) and implemented them.

A Paper Sizes
A0, A1, A2, A3, A4, A5, A6, A7, A8 paper size in mm

A paper sizes were defined by ISO216 standard, which was based on DIN476 standard of Germany, and named from A0 to A10 and after, that are: A0A1A2A3A4A5A6A7A8, A9, A10.. Georg Christoph Lichtenberg, a German scientist, once described an idea for standard paper sizes, in which the ratio of paper length to width is √2:1. He believed that this ratio could continue with the half-and-half of the paper, which was very beautiful in vision and very convenient in use. When two pieces of paper of different sizes were put together, the length of the smaller one was exactly the width of the larger one. When this standard was introduced, it was soon applied to Series B and Series C paper as well.

A Paper Sizes Rules

Nowadays, Georg’s assumption had become more detailed and accurate after becoming implementable rules. The rules of A pape sizes are as below:

  • Named from A0 to A10 and even after: A0A1A2A3A4A5A6A7A8, A9, A10..
  • S(A0) = Exactly 1 square meter (S means total area)
  • The length of the sheet is equal to its width times 1.4142. (√2:1)
  • An is divided into two equal parts of A(n-1) size, so
  • S(An) = 2 x S[A(n-1)]

A Paper Sizes Chart | Table
Dimensions of A Series Paper Sizes in inches, mm, cm, and pixels

The following is a table of A paper dimensions, through which you can find the data applied to different dimensions, including inches, mm and cm.

A paper Sizes Chart
A paper Sizes Chart – A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 paper size in inches, mm, and cm
Special: 2A0 and 4A0

The 2A0 and 4A0 are still in scope of DIN476 but are not included in the A series paper sizes of ISO216 standard. As the name implies, they are twice and four times the size of A0, and the aspect ratio remains √2:1 (that is 1.4142). Sometimes when you see a size like A00, it refers to 2A0; but there is no such expression as A0000 for 4A0.

Exceptions: A0+, A1+ and A3+

There might be confusion- the A0+, A1+ and A3+ are actually not in the scope of DIN476 standard, they are of course not in the A series of ISO 216 paper size standard as well since they don’t follow the ratio of 1.4142, although they use A as the size model. We list them here for your reference only.

Usage of A Series Paper

Now A4 size is the most widely used paper size in A paper sizes. It is widely used in government and office work in most countries except North America, and A4 paper is the most consumed paper types in the world. A1 size is mostly used for architects’ architectural design work and painters’ painting work. A2 size and A3 size are mostly used for artworks. A5, A6 and a7 size are used to send cards to greeting cards or other commercial purposes. A9 and A10, as the smallest ones of Series A paper, can be used as reminder notes.

Dimension Tolerance of A Series Paper

In our daily work and life, we don’t pay special attention to the size tolerance of the paper we use, because the paper we use is already a complete product of industrial industry. But in fact, in the process of paper making, there will still be errors due to the mistakes of machine and human operation. ISO standards allow such size tolerances for A series paper, as follows.

  1. When both the length and width are less than 150 mm (5.9 in), the tolerance is ±1.5 mm (0.06 in)
  2. When both the length and width are between 150 mm and 600 mm (5.9 in and 23.6 in), the tolerance is ±2 mm (0.08 in) 
  3. When both the length and width exceed 600 mm (23.6 in), the tolerance is ±3 mm (0.12 in)

A Paper Sizes Areas

Theoretically, the standard size of a piece of A0 paper should be one square meter, and the area will be multiplied by double for an additional size, and halved for a reduced size, but in fact, there are subtle differences.

A Paper Size Areas
A Paper Sizes Areas

RA & SRA Paper Sizes

In commercial printing, the size of A series paper is often wasted at the edges due to ink seepage in the printing process. After trimming, the remaining qualified paper is usually smaller than the standard A size. Therefore, professionals have introduced the untrimmed sizes, RA and SRA. RA means “raw format A”; and SRA means “supplementary raw format A”.

RA & SRA Paper Sizes Chart
RA & SRA Paper Sizes Chart

Defined by ISO217, both sizes are slightly larger than the A size of same size #. So it is possible to cut the excess ink out of the paper at the end of the printing, and the rest is right standard A series size.

  • S(RAn)=S(An)x1.05
  • S(SRAn)=S(An)x1.15

RA & SRA paper sizes follow the same aspect ratio as A paper, that is 1.4142.  (√2:1)


Please let us know if you want to know more about A paper sizes, or kindly help us correct the information if you find there is anything inaccurate.

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