In 1992, the American National Standards Institute adopted ANSI/ASME Y14.1 Decimal Inch Drawing Sheet Size and Format, which defined a regular series of paper sizes based upon the de facto standard  in × 11 in "letter" size to which it assigned the designation "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.

ANSI/ASME Y14.1 has been revised or updated in 1995, 2005, 2012 and 2022. It had an accompanying standard, ANSI/ASME Y14.1M, that defined metric drawing paper sizes based upon ISO 216 and ISO 5457. ASME Y14.1 and ASME Y14.1M have now been revised and consolidated into one document, ASME Y14.1-2020, Drawing Sheet Size and Format, published on 18 December 2020.

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.

+ ANSI/ASME Y14.1 inch-based drawing paper sizes Name in × in mm × mm Ratio Alias Similar ISO A sizeANSI A × 11 216 × 279 = 1.2941 Letter A4ANSI B 11 × 17 279 × 432 = 1.5455 Ledger A3ANSI C 17 × 22 432 × 559 = 1.2941 A2ANSI D 22 × 34 559 × 864 = 1.5455 A1ANSI E 34 × 44 864 × 1118 = 1.2941 A0ANSI F 28 × 40 711 × 1016 = 1.4286 A0ANSI G 11 × 22.5–90 279 × 572–2286 ANSI H 28 × 44–143 711 × 1118–3632 ANSI J 34 × 55–176 864 × 1397–4470 ANSI K 40 × 55–143 1016 × 1397–3632

Size F does not continue the alphabetic series, because it does not exhibit the same aspect ratios.

Sizes G, H, J and K are roll formats. G size is 11 in (279.4 mm) high, but variable width up to 90 in (2286 mm) in increments of  in. 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).

+ ANSI/ASME Y14.1M metric drawing paper sizes Name mm × mm Ratio A0 841 × 1189 :1 A1 594 × 841 :1 A2 420 × 594 :1 A3 297 × 420 :1 A4 210 × 297 :1 A1.0 594 × 1189 2:1 A2.1 420 × 841 2:1 A2.0 420 × 1189 2:1 A3.2 297 × 594 2:1 A3.1 297 × 841 2:1 A3.0 297 × 1189 4:1

See also

References