Letter ( paper size ) - wikipedia Letter ( paper size ) A Letter - size page Comparison of Letter ( shaded light blue ) and Government letter sizes with some similar paper and photographic paper sizes Letter or ANSI Letter is a paper size commonly used as home or office stationery in the United States, Canada, Chile, Mexico, the Dominican Republic and the Philippines. It measures 8.5 by 11.0 inches ( 215.9 by 279.4 mm ). US Letter size paper is a standard defined by the American National Standards Institute ( ANSI, paper size A ) in contrast to the A4 paper used by many other nations, adopted at varying dates, which is defined by the International Organization for Standardization ( specifically, in ISO 216 ). Details Ronald Reagan made this the paper size for U.S. federal forms in the early 1980s ; previously, the smaller `` official '' Government letter size, 8.0 by 10.5 inches ( 203 mm × 267 mm ), was used in government, while standard 8.5 × 11 inch paper was used by most other offices. In the U.S., paper density is usually measured in `` pounds per ream '' ( of 500 sheets ). Typical Letter paper has a basis weight of paper of 20 or 24 pounds ( 9.1 or 10.9 kg ) -- the weight of 500 sheets ( a ream ) of 17 - by - 22 - inch ( 432 mm × 559 mm ) paper at 70 ° F ( 21.11 ° C ) and at 50 % humidity. One ream of 20 - pound Letter - sized paper weighs 5 pounds ( 2.3 kg ), and a single Letter - sized sheet of 20 - pound paper weighs 0.16 ounces ( 4.536 g ), which is equivalent to 75.19 g / m. Some metric information is typically included on American ream packaging, 20 - pound paper is also labeled as 75 g / m. The most common density of A4 paper is 80 g / m. The precise origins of the dimensions of US letter size paper ( 8.5 × 11 in ) are not known. The American Forest & Paper Association says that the standard US dimensions have their origin in the days of manual paper making, the 11 '' length of the standard paper being about a quarter of `` the average maximum stretch of an experienced vatman 's arms ''. 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 4to ( 171⁄2 `` × 221⁄2 '' ), allowing 1⁄2 '' for trimming. The related paper size known as half letter, statement, or organizer L is exactly one half of the US letter size ( 8.5 × 5.5 in ). See also ANSI / ASME Y14. 1 ISO 216 ( definition of metric paper sizes, e.g., A4 ) Paper size : loose sizes Notes ^ Jump up to : American Forest and Paper Association. `` Why is the standard paper size in the U.S. 8 1⁄2 '' x 11 `` ? ''. Archived from the original on February 20, 2012. Retrieved 2014 - 02 - 20. Jump up ^ Blocksma, Mary. Reading the Numbers. New York : Penguin Books, 1989. Jump up ^ Fyffe, Charles ( 1969 ). Basic Copyfitting. London : Studio Vista. p. 74. ISBN 0 - 289 - 79705 - 5. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Letter_(paper_size)&oldid=831042790 '' Categories : Mechanical standards Stationery Talk About Wikipedia Azərbaycanca Deutsch Esperanto 日本 語 Português Русский Українська 中文 Edit links This page was last edited on 18 March 2018, at 11 : 40. About Wikipedia

Question: how big is a sheet of printer paper
Answer: 8.5 by 11.0 inches (215.9 by 279.4 mm)