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US Series



Belonging to the ANSI series, the Letter paper size stands as a widely recognized standard in North America. This format, measuring 8.5 x 11 inches, is part of the ANSI (American National Standards Institute) A-size family. The Letter size is equivalent to an ISO B5 or slightly larger than an A4, which is part of the ISO (International Organization for Standardization) series.

The origins of this particular dimension can be traced back to the traditional manual paper production era. The length of 11 inches was approximately equal to a quarter of "the average maximum stretch of an experienced vatman's arms." This historical fact adds a touch of human element and practicality to its design.

Letter paper dimensions


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2A046.81 x 66.221189 x 1682119 x 1683370 x 4768
A120.51 x 0.7113 x 181 x 237 x 51
4A066.22 x 93.621682 x 2378168 x 2384768 x 6741
A110.71 x 1.0218 x 262 x 351 x 74
A101.02 x 1.4626 x 373 x 474 x 105
A3+12.95 x 19.02329 x 48333 x 48933 x 1369
A1+23.98 x 35.98609 x 91461 x 911726 x 2591
A0+35.98 x 50.87914 x 129291 x 1292591 x 3662
A64.13 x 5.83105 x 14811 x 15298 x 420
A55.83 x 8.27148 x 21015 x 21420 x 595
A48.27 x 11.69210 x 29721 x 30595 x 842
A311.69 x 16.54297 x 42030 x 42842 x 1191
A91.46 x 2.0537 x 524 x 5105 x 147
A216.54 x 23.39420 x 59442 x 591191 x 1684
A82.05 x 2.9152 x 745 x 7147 x 210
A123.39 x 33.11594 x 84159 x 841684 x 2384
A72.91 x 4.1374 x 1057 x 11210 x 298
A033.11 x 46.81841 x 118984 x 1192384 x 3370

Today, it serves as a default setting in most computer software applications and printers across North America. Its widespread use extends from personal letters and business correspondence to official documents and academic papers.

Despite its regional popularity, it's worth noting that the Letter size may not align perfectly with international standards due to its unique dimensions. Therefore, when dealing with international documents or designing for global audiences, considering ISO standard sizes like A4 might be more appropriate.

Understanding these nuances about paper sizes such as 'Letter' can significantly impact how effectively your content fits and appears on printed media - whether it's a simple letter or complex marketing material.

Other Formats in the US Series

Interesting facts about Letter

1: The Origin of Letter Paper

Letter paper, also known as US Letter or American Quarto, has its roots in the British Empire. It was first used in the 18th century by English papermakers who adopted a standard size for business and personal correspondence.

2: The Dimensions of Letter Paper

The dimensions of letter paper are standardized at 8.5 inches by 11 inches (215.9 mm by 279.4 mm). This aspect ratio of approximately 1:1.294 is unique to letter-sized paper and differs from other international standards.

3: The ANSI Standardization

In the United States, the American National Standards Institute (ANSI) officially adopted letter-sized paper as a standard in 1995. This standardization aimed to ensure compatibility across various printing and copying devices.

4: Compatibility with Typewriters

The dimensions of letter-sized paper were chosen to accommodate typewriters commonly used during the early days of office automation. These machines required a specific width and length to function properly.

5: International Variations

The United States and Canada primarily use letter-sized paper, while most other countries around the world follow ISO standards such as A-series papers (A3, A4, etc.). This difference can sometimes cause compatibility issues when printing or sharing documents internationally.

6: Legal Paper's Relation to Letter Paper

A related size to letter paper is legal-sized paper, which measures at approximately 8.5 inches by 14 inches (215.9 mm by 355.6 mm). Legal-sized paper is simply an extension of letter-sized paper designed to provide more vertical space for legal documents.

7: The Impact on Stationery

The standardization of letter-sized paper greatly influenced the stationery industry. It led to the production of pre-cut letterhead paper, envelopes, and other office supplies specifically tailored to fit this size.

8: The Transition from Foolscap

Prior to the adoption of letter-sized paper, a similar but slightly larger size called foolscap was commonly used in Britain and its colonies. The transition to letter paper marked a shift towards a more standardized and efficient system.

9: Letter Paper's Popularity

Letter-sized paper remains widely popular in North America due to its historical usage and compatibility with various office equipment. It is the default size for most home printers and is commonly used for everyday printing needs.

10: Digital Age Challenges

In today's digital age, where electronic communication prevails, the demand for physical letter-sized paper has decreased. However, it still holds significance in legal documents, formal letters, business reports, and other professional settings.