What are the Different Paper Sizes?
The size of sheets of paper used as writing paper, stationery, cards, and for certain printed documents are governed by paper size standards. The international standard for paper size is the ISO 216 standard, which includes the widely used A4 page size. It is used worldwide, except in North America and parts of Central and South America, where we have North American paper sizes such as "Letter" and "Legal" is used.
The best way to describe the aspect ratio of A sizes is to compare two of a single scale with one of the next sizes. For example, 2 x side-by-side A4 page size (portrait) will be equal to 1 x page A3 and 2 x side-by-side A3 page size (portrait) will be equal to 1 x page A2 size dimensions. The bigger the paper size, the smaller the volume - the smallest is A10, and the largest is A0.
Paper Size Dimensions:
(Image will be uploaded soon)
In a letter written on 25 October 1786 by the German scientist Georg Christoph Lichtenberg to Johann Beckmann, the oldest recorded mention of the advantages of basing a paper size on an aspect ratio of \[\sqrt{2}\] can be found. The formats that became ISO paper sizes A2, A3, B3, B4, and B5 were developed in France. They were mentioned in a law of 1798 on publication taxation that was partly based on page sizes.
Types
A2 Size Dimensions: 420 × 594 mm or 16.5 × 23.4 inches measures an A2 sheet of paper. Two A3 page size will be formed by splitting these in half. In a C2 envelope, an A2 piece of paper would fit in. It will fit into a C3 envelope when folded in half. A2 is part of the A-series and is specified by the international standard for paper size, ISO 216.
A3 Size Dimensions: An A3 page size piece measures 297 × 420 mm or 11.7 × 16.5 inches in height. Two A4 sheets of paper will be formed by cutting them in half. In a C3 envelope, an A3 piece of paper would fit in. It will fit into a C4 envelope when folded in half. A3 is part of the A-series and is specified by the international standard for paper size, ISO 216.
A4 Size Dimensions: 210 × 297 mm or 8.3 × 11.7 inches measures an A4 piece of paper. Two A5 sheets of paper would be formed by cutting it in half. In a C4 envelope, an A4 piece of paper would fit in. It will fit into a C5 envelope when folded in half. A4 is part of the A-series and is specified by the international standard for paper size, ISO 216.
Difference Between A3 and A4 Size
(Image will be uploaded soon)
Properties
The aspect ratio of paper in the A series format is \[\sqrt{2}\] (approximately 1,414, when rounded). Before rounding to the nearest millimetre, A0 is specified so that it has an area of 1 m2. Successive paper sizes in the series (A1, A2, A3, etc.) are described by halving and rounding down the area of the previous paper size so that A(n + 1)'s long side is the same length as An's short side.
(Image will be uploaded soon)
Advantages
Scaling is the key benefit of this method. The special property of rectangular paper with an aspect ratio of \[\sqrt{2}\] is that when cut or folded halfway between its longer sides, each half has the same aspect ratio of \[\sqrt{2}\] as the whole sheet before it was broken.
Application
The ISO 216 formats are arranged around the 1: \[\sqrt{2}\] ratio; two sheets have the same ratio together, horizontally, next to each other. Two A4 sheets reduced to A5 size fit exactly on one A4 sheet in scaled photocopying, for example, A4 page size in magnified size fits on an A3 page size; there is neither waste nor want in each case.
FAQs on Paper Sizes
1. What are the most common standard paper sizes used around the world?
The most widely used standard is the ISO A-series, which includes the very common A4 size, used almost everywhere globally. The other major standard is the North American system, which includes sizes like Letter (8.5 x 11 inches) and Legal, primarily used in the USA, Canada, and some other countries.
2. What are the exact dimensions of an A4 sheet of paper?
An A4 sheet of paper has the following standard dimensions, making it ideal for everyday printing and documents:
- 210 × 297 millimetres (mm)
- 21.0 × 29.7 centimetres (cm)
- 8.27 × 11.69 inches
3. How are the different sizes in the 'A' series (like A0, A1, A2) related to each other?
The A-series is based on a simple system. The largest size is A0. If you cut an A0 sheet in half along its longer side, you get two A1 sheets. If you cut an A1 sheet in half, you get two A2 sheets, and this pattern continues. This means each numbered size is exactly half the area of the previous one.
4. Which paper is bigger, A4 or A5, and why?
A4 paper is bigger than A5 paper. The reason is in the numbering system: a smaller number means a larger sheet. An A5 sheet is created by folding an A4 sheet in half, which means an A4 sheet is exactly double the size of an A5 sheet.
5. What is the difference between the A-series and B-series paper sizes?
The main differences are their size and common use. The A-series (like A4, A3) is used for general printing of letters and documents. The B-series (like B4, B5) papers are slightly larger than their A-series counterparts and are often used for posters, books, and passports where a different dimension is needed.
6. Why do different parts of the world use different paper size standards, like A4 vs. Letter?
This is mainly due to historical reasons. The ISO A-series (used for A4) was designed with a mathematical logic that makes scaling documents easy and was adopted internationally. In contrast, the North American 'Letter' size came from older, traditional paper-making methods and was already the standard there before the A-series became globally popular.
7. What are some real-world examples of how different paper sizes are used?
Different paper sizes are chosen for specific tasks. Here are a few common examples:
- A3: Often used for architectural drawings, diagrams, and large charts.
- A4: The standard for school assignments, reports, and everyday office printing.
- A5: Commonly used for notepads, diaries, and small booklets.
- A6: Used for making postcards and small flyers.
8. What is special about the shape of A-series paper?
The shape, or aspect ratio, of all A-series paper is based on the square root of 2. This unique property means that when you cut a sheet in half to get the next size down (for example, from A3 to A4), the new, smaller sheet has the exact same proportions. This makes it very easy to scale documents up or down without any distortion.
