Difference between A4, Foolscap, Letter and Legal Paper Size

Key difference: Papers of specific sizes and dimensions are used for different purposes. Accordingly, the dimensions of A4, foolscap, letter and legal size papers are 210 x 297 mm, 203 x 330 m, 216 x 279 mm, and 216 x 356 mm respectively.

A4 size paper became a standard in the late 1970's. A4 is clearly the most important paper for daily office use. They are categorized under The International Organization for Standardization (ISO), which issues formal standards for measurements. Its dimensions are derived from a specific ratio 1: √ 2 (square root of 2), which was implemented to obtain perfection. It’s the business letter size in many English speaking countries.

Foolscaps were used for everyday official purposes in the mid 1980's. They were traditional papers used in their times. They were used as a supplement to the A4 size papers. Nowadays, they are no more used for any official purposes. They became a standard paper size during the 15th century, when they were produced in Germany. Nowadays, they are very rarely used.

Letter or US Letter is the common paper size used for official purposes in the North-American countries. They are only officially used in the USA and Canada, which are the only two countries who have not officially adopted the ISO standard paper sizes. These are based upon the standards of ANSI/ASME Y14.1.

Legal size papers are the common size papers in the US, called as the Legal size paper (US Legal). They are a part of the Imperial Measurement and have been determined by the North American papers and standards. These papers are complex to use due to their sizes and dimensions.


Comparison between A4, Foolscap, Letter and Legal Paper Sizes:


A4 Paper Size

Foolscap Paper Size

Letter Paper Size

Legal Paper Size

Business definitions

The standard size of typing paper adopted by the International Standards Organization.


Alternative name for legal size paper.

Non-ISO size typing and printing paper used almost exclusively in the US and some neighboring countries.

Paper measuring 8.5 inches wide and 14 inches long. Also called foolscap size paper.


Dr. Porstmann of Germany published a document proposing a standard for paper in 1920’s.

It was found to be in the earliest examples, which were firmly dated in Germany in 1479.

Ronald Reagan made this the paper size for U.S. federal forms in the early 1980s. It was officially accepted around 1921.

The United States trace their origin to the Committee on the Simplification of Paper Sizes that was formed in the Bureau of Standards in 1921.

Formalized by

They are formalized by the ISO formal standards.

They were formalized from the old British Imperial paper sizes.

They are defined by American National Standards Institute (ANSI).

They are formalized by the ANSI Y14.1M – Metric Drawing Sheet Size & Format.

Width x Height (in mm)

210 x 297 mm

203 x 330 mm

216 x 279 mm

216 x 356 mm

Width x Height (in)

8.3 x 11.7 in

8.0 x 13.0 in

8.5 x 11.0 in

8.5 x 14.0 in

Aspect Ratio





Area (sq yd)

0.074 sq yd

0.080 sq yd

0.072 sq yd

0.092 sq yd


A4 paper size is used internationally in the countries such as:

Australia, New Zealand, UK and many South American countries such as: Mexico, Costa Rica, Chile, Venezuela and more.

They were traditional paper size used in Europe and the (British) Commonwealth.

Letter sized are used in the countries like: United States, Canada, Mexico, Bolivia, Colombia, Venezuela, the Philippines and Chile.

This paper is used in the countries such as:

North America, including the US Canada and

Parts of Mexico.

Also known as

They are commonly known as the A-series.

They are commonly known as Foolscap folio.

They are known as ANSI A or American Quarto.

They are known as US Legal.


Letters, magazines, forms, catalogs, laser printer and copying machine output.

Earlier for the official purposes but now used for assignment.

They are used of official purposes.

Brochures and

Legal documents.

Image Courtesy: theinternetprinter.com.au, stationery.indiabizclub.com, graphic-design-employment.com

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