Architectural Paper Sizes ANSI

Architectural Paper Sizes

North America also has a special series of paper sizes defined for architectural purposes, in general these have aspect ratios of 4:3 or 3:2. These aspect ratios are very similar to the aspect ratio used for computer screens.

 The following table gives details of the sizes for architectural paper.

Size Width x Height (mm) Width x Height (in) Aspect Ratio
Arch A 229 x 305 mm 9.0 x 12.0 in 4:3
Arch B 305 x 457 mm 12.0 x 18.0 in 3:2
Arch C 457 x 610 mm 18.0 x 24.0 in 4:3
Arch D 610 x 914 mm 24.0 x 36.0 in 3:2
Arch E 914 x 1219 mm 36.0 x 48.0 in 4:3
Arch E1 762 x 1067 mm 30.0 x 42.0 in 7:5

ANSI Standard Paper Sizes

ANSI (American National Standards Insitute) defined a regular series of paper sizes based around the Letter (8.5" x 11") format, with this becoming the A sizes and larger sizes being B,C,D & E. Surprisingly these ANSI standard sizes were defined in 1995 well after the ISO standard sizes.

Unlike the ISO standard sizes which have the single aspect ratio of 1:root2, ANSI standard sizes have two aspect ratios 1:1.2941 and 1:1.5455 which means that enlarging and reducing between the sizes is not as easy as with the ISO sizes and leaves wider margins on the enlarged/reduced document.

Size Width x Height (mm) Width x Height (in) Aspect Ratio Nearest ISO
A 216 x 279 mm 8.5 x 11.0 in 1:1.2941 A4
B 279 x 432 mm 11.0 x 17.0 in 1:1.5455 A3
C 432 x 559 mm 17.0 x 22.0 in 1:1.2941 A2
D 559 x 864 mm 22.0 x 34.0 in 1:1.5455 A1
E 864 x 1118 mm 34.0 x 44.0 in 1:1.2941 A0