In the American continent, a different system of paper measurements is used than the rest of the world. The types and dimensions of paper on the American scale are:
Letter Oficio (also known as folio)
letters
legal tabloid
These formats and measures are different from the international standard, known as ISO 216 or European format. However, in many cases “equivalences” are used, such as the use of letter size instead of A4 format (one of the most widely used in the world), although their measurements are not the same.
Measurements of letter size paper, legal, letterslegal and tabloid
Paper size Millimeters Centimeters Inches Letter 220 x 280 mm 22 x 28 cm 8.6 x 11 inches Oficio (folio) 220 x 340 mm 22 x 34 cm 8.6 x 13.3 inches
letters
216 x 279mm
21.6 x 27.9cm
8.5 x 10.9 in. Legal 216 x 356 mm 21.6 x 35.6 cm 8.5 x 14 in. Tabloid 279.4 x 431.8 mm 27.9 x 43.1 cm 11 x 17 in
Letter sizes and letters are almost the same, so they are considered and used as the same format.
Difference between the paper formats of the European system (A4) and the American system (letter)
Difference between letter, folio and legal size and DIN A series
In Canada, the United States, and almost all Latin American countries, letter, letters, legal and tabloid, based on the American metric system. These formats are in inches and differ substantially from the world standard, not only in the unit of measurement, but also in the proportions of the paper.
This system has been used for decades in the mentioned countries, but it was only in 1995 that the ANSI (American National Standards Institute) included these paper measures in its classification.
For its part, the European system of paper sizes emerged at the end of the First World War as a practical solution to avoid wasting this resource.
This system, which was originally called DIN 476, was created by the German engineer Walter Porstmann, who established the sheet formats that are known today as the A, B and C series. Of these, the most popular is the A series. because it contains the most used page measurements on a day-to-day basis, such as the A4 format (used in printers, photocopiers, writing documents, etc.).
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Paper sizes and ISO 216 standard
The paper measurement system created by Walter Porstmann in the postwar period under the name DIN 476 proved to be efficient over time. The International Organization for Standardization (ISO), in charge of standardizing standards for process optimization, adopted this system to create the ISO 216 standard. This standard is used in almost the entire world, except in the vast majority of the American continent.
This means that the paper formats of the A series, the DIN 476 standard and the ISO 216 standard refer to the same thing.
In many cases, for practical reasons, substitutions are made between formats of the American and European systems. That is the reason why letter size (American system) is often used as a substitute for A4 (European system) and vice versa.
However, the measurements between the two are different. By not knowing these specifications, mistakes can be made that imply large-scale economic losses (as in the case of the graphic or publishing industry).
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