Letter (paper size)

Letter (officially ANSI A) is a paper size standard defined in ANSI/ASME Y14.1 by the American National Standards Institute, commonly used as home or office stationery primarily in the United States, Canada, and the Philippines, and variably across Latin America.

The Reagan administration made Letter-size paper the norm for US federal forms in the early 1980s; previously, the smaller "official" Government Letter size, 8 by 10.5 inches (203.2 by 266.7 mm) (aspect ratio: 1.3125), was used in government, while 8.5-by-11-inch (215.9 by 279.4 mm) paper was standard in most other offices.

Some metric information is typically included on American ream packaging.

The American Forest & Paper Association says that the standard US dimensions have their origin in the days of manual papermaking, the 11-inch length of the standard paper being about a quarter of "the average maximum stretch of an experienced vatman's arms".

[2] The letter size falls within the range of the historical quarto size, which since pre-modern times refers to page sizes of 8 to 9 inches (200 to 230 mm) wide and 10 to 11 inches (250 to 280 mm) high, and it is indeed almost exactly one quarter of the old Imperial (British) paper size known as demy quarto – 17+1⁄2 by 22+1⁄2 inches (440 by 570 mm) – allowing a 1⁄2 inch (13 mm) for trimming.