Letter (officially ANSI A) is a

paper size Paper size refers to Technical standard, standardized dimensions for sheets of paper used globally in stationery, printing, and technical drawing. Most countries adhere to the ISO 216 standard, which includes the widely recognized A series ( ...

standard defined in ANSI/ASME Y14.1 by the

American National Standards Institute The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...

, commonly used as home or office stationery primarily in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, and the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

, and variably across

Latin America Latin America is the cultural region of the Americas where Romance languages are predominantly spoken, primarily Spanish language, Spanish and Portuguese language, Portuguese. Latin America is defined according to cultural identity, not geogr ...

."US Letter" is the primary paper size used in Belize, Canada, Chile, Colombia, Costa Rica, El Salvador, Guatemala, Mexico, Nicaragua, Panama, Philippines, Puerto Rico, United States, Venezuela according to It measures and is similar in use to the

A4 paper ISO 216 is an International Organization for Standardization, international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, wh ...

standard at used by most other countries, defined in

ISO 216 ISO 216 is an international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, which includes the A4, the most commonly availabl ...

by the

International Organization for Standardization The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. M ...

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The

Reagan administration Ronald Reagan's tenure as the 40th president of the United States began with his first inauguration on January 20, 1981, and ended on January 20, 1989. Reagan, a Republican from California, took office following his landslide victory over ...

made Letter-size paper the norm for US federal forms in the early 1980s; previously, the smaller "official" Government Letter size, (aspect ratio: 1.3125), was used in government, while paper was standard in most other offices. The

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

is ≈ 1.294 and the

diagonal In geometry, a diagonal is a line segment joining two vertices of a polygon or polyhedron, when those vertices are not on the same edge. Informally, any sloping line is called diagonal. The word ''diagonal'' derives from the ancient Greek � ...

is ≈ in length. In the US, paper density is usually measured in "pound per reams" (of 500 sheets). Typical Letter paper has a

basis weight of paper Grammage and basis weight, in the pulp and paper industry, are the area density of a paper product, that is, its mass per unit of area. Two ways of expressing the area density of a paper product are commonly used: * Expressed in grams (g) per squ ...

of – the weight of 500 sheets (a ream) of paper at and at 50% humidity. One ream of 20-pound Letter-sized paper weighs , and a single Letter-sized sheet of 20-pound paper weighs , which is equivalent to 75.19 g/m². Some metric information is typically included on American ream packaging. For example, 20-pound paper is also labeled as 75 g/m². The most common density of A4 paper is 80 g/m². The related paper size known as

Invoice An invoice, bill, tab, or bill of costs is a commercial document that includes an itemized list of goods or services furnished by a seller to a buyer relating to a sale transaction, that usually specifies the price and terms of sale, quanti ...

(colloquially Half Letter) is exactly one half of the US Letter size: .

History

The precise origins of the dimensions of US letter-size paper (8.5 × 11 in) are not known. The

American Forest & Paper Association The American Forest & Paper Association (AF&PA) is the national trade association of the paper and wood products industry. AF&PA was formed on January 1, 1993, by the merger of the National Forest Product Association and the American Paper Ins ...

says that the standard US dimensions have their origin in the days of manual

papermaking Papermaking is the manufacture of paper and cardboard, which are used widely for printing, writing, and packaging, among many other purposes. Today almost all paper is Pulp and paper industry, made using industrial machinery, while handmade pape ...

, the 11-inch length of the standard paper being about a quarter of "the average maximum stretch of an experienced

vatman Decimo Ltd was a British electronics manufacturer. Decimo was founded by Douglas Dorsett in the 1970s, and the company was based in Luton, Bedfordshire, England. Vatman Vatman was a brand of pocket calculator An electronic calculator is ...

's arms". The letter size falls within the range of the historical

quarto Quarto (abbreviated Qto, 4to or 4º) is the format of a book or pamphlet produced from full sheets printed with eight pages of text, four to a side, then folded twice to produce four leaves. The leaves are then trimmed along the folds to produc ...

size, which since pre-modern times refers to page sizes of wide and high, and it is indeed almost exactly one quarter of the old Imperial (British) paper size known as ''demy quarto'' – – allowing a for trimming.

References

{{Reflist Mechanical standards Stationery Printing Paper

Details

History

See also

References