A4 Paper Size

What is A4 Paper Size?

A4 size is one of the paper sizes in the ISO A series. its specific dimensions are 8.27″ x 11.69″ in inches, 210 x 297 in mm, or 21.0 x 29.7 in cm.

The size of the A paper series was defined by ISO216, which was first put forward by German scientist Georg Christoph Lichtenberg as DIN476 standard of Germany and later adopted by ISO. Under the same standard, there is also B size series, which follows the same rule as A series: ratio of length to width of a piece of paper should be √2:1.

Physically, a piece of A4 paper can be folded twice to fit fully into a C6 envelope.

Layout

The figure below shows A4 dimensions in inches and mm. In cm it is 21.0 x 29.7cm, dividing its dimensions in mm by 10.

Regions

As in the scope of ISO paper sizes, A4 size is used in most countries and regions in the world, except North American countries, Mexico, Philippines, and other countries affected by American colonization. In these areas, US paper sizes are the most widely used, which belong to a different system.

Usage

Like its North American alternative the letter size, A4 size is the most common paper size in office use, educational settings, business documents, laws and regulations, government reports, leaflets, restaurant menus and other uses.

A4 Size in Inches

8.27″ x 11.69″

In inches, the dimensions of A4 paper are 8.27 inches in width and 11.69 inches in height. Inches are not the preferred unit for expressing the size of A4 paper, as most of the countries where A4 paper is popular are metric volume-using countries. However, inches are used in order to give imperial size countries a better understanding of the size and an idea of its magnitude. Its format and dimensions in inches make it versatile, fitting easily into standard printers, binders, and document folders.

A4 Size in cm

21.0cm  x 29.7cm

A4 paper measures 21.0 cm in width and 29.7 cm in height. The metric-based system of centimeters offers a precise and universally recognized measurement, making it ideal for businesses, governments, and educational institutions around the world. The dimensions of A4 in centimeters are a bit more intuitive in countries that use the metric system. The size is often used for both digital and printed materials, from official documents to creative projects, due to its perfect balance of usability and convenience.

A4 Size in mm

210mm x 297mm

When measured in millimeters, A4 paper measures 210 mm in width and 297 mm in height. This is the most detailed and accurate way to describe A4 paper dimensions, as millimeters provide a finer level of precision compared to centimeters or inches. The metric measurement in millimeters is used in many fields such as engineering, design, and manufacturing, where exact dimensions are crucial. The dimensions in millimeters are particularly important for precise digital printing, where even small variations in size can affect the final output. In countries that follow the metric system, millimeters are the standard unit for paper dimensions, making A4 an easy-to-understand and globally accepted size.

A4 Dimensions Table

A4 Dimensions in Pixels

A4 dimensions vary in pixels, depending on the PPI/DPI applied.

* PPI (pixels per inch) = DPI (dots per inch) = Resolution

A Series Size Relations

The dimension aspect ratio of an ISO216 paper is √2:1, the A series paper size start from the first size, the A0 size.

Cut an A0 sized paper symmetrically at the midpoint of its long edge, you will get two A1 papers; then cut the papers you got in the same way, you will get 4 pieces of A2 sheets, and then 8 pieces of A3 sheets, and then 16 pieces of A4 sheet in the fourth cutting. Based on this scale, each size from A0 to A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, etc, is twice the one of the next code. Thus, each A4 sheet is twice the size of A5 sheets, and half the size of an A3 sheet.

The figure below reflects the relationship between the dimensions of ISO paper size A, as well as letter size (8.5″ x 11″, wider and shorter) and legal size (8.5″ x 14″, wider and longer).

A4 Size vs. Letter Paper Size (8.5×11 paper size)

The most of common A size corresponds to a similar size in North American countries, Mexico, the Philippines, and other countries affected by American colonization. For example, A3 size versus ANSI B (tabloid or Ledger, also known as 11×17 paper size), and A4 versus Letter Size.

Just as A3 size can occasionally replace tabloid or Ledger, A4 can also be used as a alternative for Letter size in some cases, and some bloggers or website writers even confuse A4 with Letter Paper size. – But they are defined by different systems and used in different regions. Although they are similar in size, they are not the same thing.

Again,

  – A4:  8.27″ x 11.69″
Used in non-North American countries, belongs to ISO A paper sizes

  – Letter Paper Size:  8.50″ x 11.00″
Specifically called ANSI A paper size, or American Quarto, used in North America, Mexico, the Philippines, etc, is part of the ANSI paper standard of US paper sizes

A4 Size: The Most Popular Paper Size in the World and Why

In non-American standard countries where ISO standard paper sizes are applicable, there are also many kinds of paper sizes to choose from. For example, only Series A has sizes from A0 to A10 or even A12; The B series has sizes with the same principle. However, A4 is chosen as the most commonly used paper for two reasons.

The most cost-effective size

This is not based on its material, but the ease of procurement and its wide applicability. At the same price, A4 paper is the paper with largest size that you can buy, on which you can print the most words and consume less for the same article, so in essence A4 paper is the most cost-effective for printing and copying.

For example, A5 size paper is only half of A4’s, but in some countries the copying price is higher than half of A4’s; A3 size paper is twice as expensive as A4, but the copying price is high than double of A4’s, so actually A4 is currently a dessert price charged for copying. Therefore, it naturally becomes the most widely used size in the world.

The ergonomic size

From the practical point of view, the size of A4 (8.27″ x 11.69″ in inches, 210 x 297 in mm, or 21.0 x 29.7 in cm) is just one of the most suitable dimensions for ergonomic comfort angle, whether it is used for writing or carrying.

Of course, there must be a size range that is most suitable for ergonomics, and fortunately A4 is exactly in this range and right the size specified by international standards. It should be noted that in North American countries, Mexico, the Philippines and other former colonial areas of the United States, people use letter paper size more as the office size, which measures 8.5″ x 11″ and is very close to A4, is just in this size range too.

In addition, from the perspective of dialectics, the more popular A4 is, the more corresponding manufacturers there are; and the mature technology and intensified competition make its production cost and selling price reach the most reasonable level, thus A4 becoming the best choice for people’s daily use.

The Size of Most Consumed Paper on The Planet and How

A4 Paper consumption: a shocking astronomical figure

Compared with any other size of paper in the world, the A4 size is the most widely used. Most countries and regions in the world use A4 paper as the main consumed paper. It also means that the world consume hundreds of thousands of tons of A4 paper every day, which is a shocking astronomical figure.

Paper consumption and deforestation

A research published in the journal Nature in September 2015 proposed the answer of how many trees are cut down for paper products every year: 15.3 billion trees. By the time this page is being updated by me today in 2024, perhaps that number had increased a lot. What is certain is that among them, a considerable part comes from the consumption of A4 paper.

Therefore, taking good use of the paper on your desk, not wasting it, is the protection of nature. It is also the responsibility of each of us.

Here you can find the dynamic paper consumption status and Hectares of forests cut down of this year.

Main Facts of A4 Size

• A4 Dimensions in inches, mm, cm
  in inches: 8.27″ x 11.69″
  in mm: 210 x 297 mm
  in cm: 21.0 x 29.7 cm
• Area: 1/16 square meter.
• Country of use: Most countries except North America
• Other name: DIN A4 Size
• Usage: Office paper in most countries in the world.
• Advantages: Suitable size for office and document signing, easy binding and carrying; No customization required, can be used in most countries internationally.
• Disadvantages: Not suitable for use in American countries.
• Ratio: It follows the ratio of ISO216 size standard, length to width: 1.414:1, or √2:1.
• Approximate American size: Letter paper size, measures 8.5″ x 11″ in inches, 216 x 279 in mm, or 21.6 x 27.9 in cm, and is slightly wider and shorter than the A4 size.

FAQs about A4 Paper Size