US Paper Sizes

North America, including the US, Canada and parts of Mexico, is the only area of the first world that doesn't use the ISO 216 standard paper sizes, instead they use Letter, Legal, Executive and Ledger/Tabloid paper sizes and those that have been formalised in ASME Y14.1 - Drawing Sheet Size & Format. ANSI also incorporates the ISO 216 standard with ASME Y14.1M - Metric Drawing Sheet Size & Format US Envelope Sizes are also non ISO 216 and are listed on this page. The following table gives the sizes in millimeters and inches of the Commonly used American paper sizes.

SizeWidth x Height (mm)Width x Height (in)Aspect Ratio
Half Letter140 x 216 mm5.5 x 8.5 in1:1.5455
Government Letter203 x 254 mm8.0 x 10.0 in1:1.25
Letter216 x 279 mm8.5 x 11.0 in1:1.2941
Junior Legal127 x 203 mm5.0 x 8.0 in1:1.6000
Government Legal216 x 330 mm8.5 x 13.0 in1:1.5294
Legal216 x 356 mm8.5 x 14.0 in1:1.6471
Ledger / Tabloid279 x 432 mm11.0 x 17.0 in1:1.5455

Of the American sizes Letter, Legal and Ledger/Tabloid are the most used in office environments. Half Letter is often used for personal letter writing, notepads and diaries. Government Letter is still widely available, however Government Legal (known as Long Bond in the Phillipines) is much less common nowadays.

The following page discusses North American paper weights in detail, as it is useful to know how weight as well as size and stock type affects your choice of paper. The difference between US Letter and Legal Paper sizes and international A4 is discussed here, however it is important to say that Letter is effectively the equivalent to A4 size in the USA.

ANSI Standard Paper Sizes

ANSI (American National Standards Institute) defined a regular series of paper sizes based around the Letter (8.5" x 11") format, with this becoming the A size and larger sizes being B,C,D & E. Surprisingly these ANSI standard sizes were defined in 1992 well after the ISO standard sizes. Letter format paper was originally defined as a national standard in 1921 and was formally adopted by the US government in the 1980's. ANSI A sized paper is commonly referred to as Letter and ANSI B as Ledger or Tabloid.

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.

SizeWidth x Height (mm)Width x Height (in)Aspect RatioClosest ISO
A216 x 279 mm8.5 x 11.0 in1:1.2941A4
B279 x 432 mm11.0 x 17.0 in1:1.5455A3
C432 x 559 mm17.0 x 22.0 in1:1.2941A2
D559 x 864 mm22.0 x 34.0 in1:1.5455A1
E864 x 1118 mm34.0 x 44.0 in1:1.2941A0

B+ (Super B)

B Plus, or Super B as it is sometimes known, has dimensions of 13" x 19" (330mm x 483mm). This size is the ANSI B size with a 1" margin for print bleed all the way round. It is sometimes known as A3+ or Super A3 in countries that use ISO 216 paper sizes. European manufacturers sometimes give this size as 330mm x 482mm.

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.

SizeWidth x Height (mm)Width x Height (in)Aspect Ratio
Arch A229 x 305 mm9.0 x 12.0 in4:3
Arch B305 x 457 mm12.0 x 18.0 in3:2
Arch C457 x 610 mm18.0 x 24.0 in4:3
Arch D610 x 914 mm24.0 x 36.0 in3:2
Arch E914 x 1219 mm36.0 x 48.0 in4:3
Arch E1762 x 1067 mm30.0 x 42.0 in7:5

Some Internet sites also list Arch E2 at 26.0 x 38.0 in (660 x 965 mm) and Arch E3 at 27.0 x 39.0 in (686 x 991 mm), however we can find no references to these sizes on the ANSI site, which lists A, B, C, D, E and E1. Additionally these two sizes don't have simple aspect ratios which are a common feature of the Arch series paper sizes. The Arch E3 size is available to buy from some paper suppliers where it is just referred to as 27 x 39 and Arch E2 doesn't appear to be available at all.


Other US Paper Size Standards

Other paper size standards issued by ANSI include:

US Paper Sizes - Quick Lookup

Select the paper size from the 'Size' selector and the unit from the 'Unit' selector - the dimensions will be shown in the dimensions box.

in is
8.5 x 11.0