ANSI/ASME Y14.1 – Paper Sizes

A size chart illustrating the ANSI sizes.

In 1995, the American National Standards Institute adopted ANSI/ASME Y14.1 which defined a regular series of paper sizes based upon the de facto standard 8½ in Ã— 11 in “letter” size which it assigned “ANSI A”. This series also includes “ledger”/”tabloid” as “ANSI B”. This series is somewhat similar to the ISO 216 standard in that cutting a sheet in half would produce two sheets of the next smaller size. Unlike the ISO standard, however, the arbitrary aspect ratio forces this series to have two alternating aspect ratios. The ANSI series is shown below.

With care, documents can be prepared so that the text and images fit on either ANSI or their equivalent ISO sheets at 1:1 reproduction scale.

Name in × in mm × mm Ratio Alias Similar ISO A size
ANSI A 8½ x 11 216 x 279 1.2941 Letter A4
ANSI B 17 x 11

11 x 17

432 x 279

279 x 432

1.5455 Ledger



ANSI C 17 x 22 432 x 559 1.2941 A2
ANSI D 22 x 34 559 x 864 1.5455 A1
ANSI E 34 x 44 864 x 1118 1.2941 A0

Other, larger sizes continuing the alphabetic series illustrated above exist, but they are not part of the series per se, because they do not exhibit the same aspect ratios. For example, Engineering F size (28 in Ã— 40 in, 711.2 mm Ã— 1016.0 mm) also exists, but is rarely encountered, as are G, H, … N size drawings. G size is 22½ in (571.5 mm) high, but variable width up to 90 in (2286 mm) in increments of 8½ in, i.e., roll format. H and larger letter sizes are also roll formats. Such sheets were at one time used for full-scale layouts of aircraft parts, wiring harnesses and the like, but today are generally not needed, due to widespread use of computer-aided design (CAD) and computer-aided manufacturing (CAM).


  1. ^ Adobe Systems Incorporated (February 9, 1996), PostScript Printer Description File Format Specification (4.3 ed.), San Jose, California, p. 191, Retrieved on 6 March 2008


This information originally retrieved from
on Wednesday 27th July 2011 7:47 pm EDT
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