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 Y14.1M - 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
Letter216 x 279 mm8.5 x 11.0 in1:1.2941
Legal216 x 356 mm8.5 x 14.0 in1:1.6471
Junior Legal127 x 203 mm5.0 x 8.0 in1:1.6000
Ledger / Tabloid279 x 432 mm11.0 x 17.0 in1:1.5455

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 sizes and larger sizes being B,C,D & E. Surprisingly these ANSI standard sizes were defined in 1995 well after the ISO standard sizes. 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" (329mm 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


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