Topic summary
Letter size
Extracted from the Wikipedia article Letter (paper size).
Details
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. The aspect ratio is 22/17 ≈ 1.294 and the diagonal is √8.5 + 11 ≈ 13.901 inches (353.1 mm) in length.