US Paper Sizes

The United States primarily uses a different system of paper sizes from most of the world. The most common US loose sizes are Letter (8.5 x 11 inches), Legal (8.5 x 14 inches), Tabloid or Ledger (11 x 17 inches), Executive (7.25 x 10.5 inches), Half Letter (5.5 x 8.5 inches), Statement or Stationery or Memo (5.5 x 8.5 inches), Government Letter (8 x 10 inches), Junior Legal (5 x 8 inches), and Government Legal or Foolscap (8.5 x 13 inches). Letter, Legal and Tabloid are the most commonly used everyday sizes. These sizes originate from manual papermaking practices and have become widespread due to the large North American market.

The American National Standards Institute's ANSI/ASME Y14.1 defines a regular series of paper sizes based on Letter size, which it assigned as ANSI A (8.5 x 11 inches). This series includes ANSI B (11 x 17 inches), ANSI C (17 x 22 inches), ANSI D (22 x 34 inches), and ANSI E (34 x 44 inches). The ANSI sizes have two alternating aspect ratios, unlike the standardized ISO sizes. ANSI sizes are intended for technical drawings.

There is also a corresponding series of Architectural paper sizes in ANSI defined with aspect ratios of 4:3 and 3:2 preferred by architects. The Architectural sizes are designated Arch A (9 x 12 inches), Arch B (12 x 18 inches), Arch C (18 x 24 inches), Arch D (24 x 36 inches), Arch E1 (30 x 42 inches), and Arch E (36 x 48 inches). The standardized sizes provide advantages for readability, handling and filing of drawings.