# Paper size

A size chart illustrating the ISO A series and a comparison with American letter and legal formats.
Comparison of some paper and photographic paper sizes close to the A4 size.

Many paper size standards conventions have existed at different times and in different countries. Today there is one widespread international ISO standard (including A4, B3, C4, etc.) and a local standard used in North America (including letter, legal, ledger, etc.). The paper sizes affect writing paper, stationery, cards, and some printed documents. The standards also have related sizes for envelopes.

## The international standard: ISO 216

### A series

The international paper size standard, ISO 216, is based on the German DIN 476 standard for paper sizes. ISO paper sizes are all based on a single aspect ratio of square root of 2, or approximately 1:1.4142. The base A0 size of paper is defined to have an area of 1 m2. With this definition and the given aspect ratio of square root of two, one can calculate the sides of an A0 sheet as follows: The long side is 1 metre multiplied by the square root of the square root (that is, the fourth root) of 2 and the short side is 1 metre divided by the same. Rounded to millimetres, the A0 paper size is 841 by 1,189 millimetres (33.1 in × 46.8 in).

Successive paper sizes in the series A1, A2, A3, and so forth, are defined by halving the preceding paper size along the larger dimension. The most frequently used paper size is A4 210 by 297 millimetres (8.3 in × 11.7 in).

The significant advantage of this system is its scaling: if a sheet with an aspect ratio of $\sqrt{2}$ is divided into two equal halves parallel to its shortest sides, then the halves will again have an aspect ratio of $\sqrt{2}$. Folded brochures of any size can be made by using sheets of the next larger size, e.g. A4 sheets are folded to make A5 brochures. The system allows scaling without compromising the aspect ratio from one size to another—as provided by office photocopiers, e.g. enlarging A4 to A3 or reducing A3 to A4. Similarly, two sheets of A4 can be scaled down and fit exactly 1 sheet without any cutoff or margins. Weights are easy to calculate as well: a standard A4 sheet made from 80 gram/m2 paper weighs 5 grams (as it is one 16th of an A0 page, measuring 1 m2), allowing one to easily compute the weight—and associated postage rate—by counting the number of sheets used.

The advantages of basing a paper size upon an aspect ratio of $\sqrt{2}$ were already noted in 1786 by the German scientist and philosopher Georg Christoph Lichtenberg.[1] Early in the 20th century, Dr Walter Porstmann turned Lichtenberg's idea into a proper system of different paper sizes. Porstmann's system was introduced as a DIN standard (DIN 476) in Germany in 1922, replacing a vast variety of other paper formats. Even today the paper sizes are called "DIN A4" (pronounced: "deen-ah-fear") in everyday use in Germany and Austria. The term Lichtenberg ratio has recently been proposed for this paper aspect ratio.

The main disadvantage of the system is type does not scale the same way; therefore, when a page is resized, the type set on it loses legibility as the proportion between the type's x-height, page margins, and leading are distorted. When trim is involved, as in the manufacture of books, ISO 216 sizes are generally too tall and narrow for book production (see: Canons of page construction). The distortion is even more pronounced with printed sheet music. European book publishers typically use metricated traditional page sizes for book production.

The DIN 476 standard spread quickly to other countries. Before the outbreak of World War II, it had been adopted by the following countries:

 Belgium (1924)Netherlands (1925)Norway (1926) Finland (1927)Switzerland (1929)Sweden (1930) Soviet Union (1934)Hungary (1938)Italy (1939)

During World War II, the standard was adopted by Uruguay (1942), Argentina (1943) and Brazil (1943); and afterwards spread to other countries:

 Spain (1947)Austria (1948)Iran (1948)Romania (1949)Japan (1951)Denmark (1953)Czechoslovakia (1953)Israel (1954)Portugal (1954)Yugoslavia (1956)India (1957) Poland (1957)United Kingdom (1959)Republic of Ireland (1959)Venezuela (1962)New Zealand (1963)Iceland (1964)Mexico (1965)South Africa (1966)France (1967)Peru (1967)Turkey (1967) Chile (1968)Greece (1970)Rhodesia (now Zimbabwe) (1970)Singapore (1970)Bangladesh (1972)Thailand (1973)Barbados (1973)Australia (1974)Ecuador (1974)Colombia (1975)Kuwait (1975)

### A4

By 1975 so many countries were using the German system that it was established as an ISO standard, as well as the official United Nations document format. By 1977 A4 was the standard letter format in 88 of 148 countries. Today the standard has been adopted by all countries in the world except the United States and Canada. In Mexico, Costa Rica, Colombia, Venezuela, Chile and the Philippines the US letter format is still in common use, despite their official adoption of the ISO standard.

### B series

A size chart illustrating the ISO B series.

In addition to the A series, there is a less common B series. The area of B series sheets is the geometric mean of successive A series sheets. So, B1 is between A0 and A1 in size, with an area of 0.707 m2 ($\sqrt{1/2}$ m2). As a result, B0 is 1 metre wide, and other sizes in the B series are a half, a quarter or further fractions of a metre wide. While less common in office use, it is used for a variety of special situations. Many posters use B-series paper or a close approximation, such as 50 cm × 70 cm; B5 is a relatively common choice for books. The B series is also used for envelopes and passports. The B-series is widely used in the printing industry to describe both paper sizes and printing press sizes, including digital presses. B3 paper is used to print two US letter or A4 pages side by side using imposition; four pages would be printed on B2, eight on B1, etc.

### C series

A size chart illustrating the ISO C series.

The C series is used only for envelopes and is defined in ISO 269. The area of C series sheets is the geometric mean of the areas of the A and B series sheets of the same number; for instance, the area of a C4 sheet is the geometric mean of the areas of an A4 sheet and a B4 sheet. This means that C4 is slightly larger than A4, and B4 slightly larger than C4. The practical usage of this is that a letter written on A4 paper fits inside a C4 envelope, and a C4 envelope fits inside a B4 envelope.

ISO paper sizes (plus rounded inch values)
FormatA seriesB seriesC series
Sizemm × mmin × inmm × mmin × inmm × mmin × in
0841 × 118933.11 × 46.811000 × 141439.37 × 55.67917 × 129736.10 × 51.06
1594 x 84123.39 × 33.11707 × 100027.83 × 39.37648 × 91725.51 × 36.10
2420 × 59416.54 × 23.39500 × 70719.69 × 27.83458 × 64818.03 × 25.51
3297 × 42011.69 × 16.54353 × 50013.90 × 19.69324 × 45812.76 × 18.03
4210 × 2978.27 × 11.69250 × 3539.84 × 13.90229 × 3249.02 × 12.76
5148 × 2105.83 × 8.27176 × 2506.93 × 9.84162 × 2296.38 × 9.02
6105 × 1484.13 × 5.83125 × 1764.92 × 6.93114 × 1624.49 × 6.38
774 × 1052.91 × 4.1388 × 1253.46 × 4.9281 × 1143.19 × 4.49
852 × 742.05 × 2.9162 × 882.44 × 3.4657 × 812.24 × 3.19
937 × 521.46 × 2.0544 × 621.73 × 2.4440 × 571.57 × 2.24
1026 × 371.02 × 1.4631 × 441.22 × 1.7328 × 401.10 × 1.57

The tolerances specified in the standard are

• ±1.5 mm (0.06 in) for dimensions up to 150 mm (5.9 in),
• ±2 mm (0.08 in) for lengths in the range 150 to 600 mm (5.9 to 23.6 in) and
• ±3 mm (0.12 in) for any dimension above 600 mm (23.6 in).

### German extensions

The German standard DIN 476 was published in 1922 and is the original specification of the A and B sizes. It differs in two details from its international successor:

DIN 476 provides an extension to formats larger than A0, denoted by a prefix factor. In particular, it lists the two formats 2A0, which is twice the area of A0, and 4A0, which is four times A0:

DIN 476 overformats
Namemm × mmin × in
4A01682 × 237866.22 × 93.62
2A01189 × 168246.81 × 66.22

DIN 476 also specifies slightly tighter tolerances:

• ±1 mm (0.04 in) for dimensions up to 150 mm (5.9 in),
• ±1.5 mm (0.06 in) for lengths in the range 150 mm to 600 mm (5.9 to 23.6 in) and
• ±2 mm (0.08 in) for any dimension above 600 mm (23.6 in).

### Swedish extensions

Comparison of ISO 216 and Swedish standard SIS 014711 paper sizes between A4 and A3 sizes.

The Swedish standard SIS 014711 generalized the ISO system of A, B, and C formats by adding D, E, F, and G formats to it. Its D format sits between a B format and the next larger A format (just like C sits between A and the next larger B). The remaining formats fit in between all these formats, such that the sequence of formats A4, E4, C4, G4, B4, F4, D4, H4, A3 is a geometric progression, in which the dimensions grow by a factor 21/16 from one size to the next. However, the SIS 014711 standard does not define any size between a D format and the next larger A format (called H in the previous example). Of these additional formats, G5 (169 × 239 mm) and E5 (155 × 220 mm) are popular in Sweden for printing dissertations,[citation needed] but the other formats have not turned out to be particularly useful in practice and they have not been adopted internationally.

### Japanese B-series variant

The JIS defines two main series of paper sizes. The JIS A-series is identical to the ISO A-series, but with slightly different tolerances. The area of B-series paper is 1.5 times that of the corresponding A-paper (instead of the factor 1.414... for the ISO B-series), so the length ratio is approximately 1.22 times the length of the corresponding A-series paper. The aspect ratio of the paper is the same as for A-series paper. Both A- and B-series paper is widely available in Japan, Taiwan and China, and most photocopiers are loaded with at least A4 and either one of A3, B4 and B5 paper.

There are also a number of traditional paper sizes, which are now used mostly only by printers. The most common of these old series are the Shiroku-ban and the Kiku paper sizes.

JIS paper sizes (plus rounded inch values)
FormatB seriesShiroku banKiku
Sizemm × mmin × inmm × mmin × inmm × mmin × in
01030 × 145640.55 × 57.32
1728 × 103028.66 × 40.55
2515 × 72820.28 × 28.66
3364 × 51514.33 × 20.28
4257 × 36410.12 × 14.33264 × 37910.39 × 14.92227 × 3068.94 × 12.05
5182 × 2577.17 × 10.12189 × 2627.44 × 10.31151 × 2275.94 × 8.94
6128 × 1825.04 × 7.17127 × 1885.00 × 7.40
791 × 1283.58 × 5.04
864 × 912.52 × 3.58
945 × 641.77 × 2.52
1032 × 451.26 × 1.77
1122 × 320.87 × 1.26
1216 × 220.63 × 0.87

### Colombian common sizes naming

The most common paper sizes used for commercial and industrial printing in Colombia are close to the ISO B1, B2 and B3 and are referred to as pliego, ¹⁄₂ pliego and ¹⁄₄ pliego respectively. The "Super-B" size is known as extratabloide.

Colombian paper sizes
Sizemm × mm
Pliego700 x 1000
¹⁄₂ pliego500 x 700
¹⁄₄ pliego350 x 500
Extratabloide440 x 380

## North American paper sizes

### Loose sizes

Current standard sizes of U.S., Canadian and Mexican paper are a subset of the traditional inch-based sizes described below. "Letter", "legal", "ledger", and "tabloid" are by far the most commonly used of these for everyday activities. The origins of the exact dimensions of "letter" size paper (812 in × 11 in or 215.9 mm × 279.4 mm) are lost in tradition and not well documented. The American Forest and Paper Association argues that the dimension originates from the days of manual paper making, and that the 11 inch length of the page is about a quarter of "the average maximum stretch of an experienced vatman's arms."[2] However, this does not explain the width or aspect ratio. Outside of North America, Letter size is also known as "American Quarto"[3] and the size is indeed almost exactly a quarter of the old Imperial (British) paper size known as Demy 4to (17½"×22½"), allowing ½" for trimming.[4]

North American paper sizes
Sizein × inmm × mm
Letter8.5 × 11215.9 × 279.4
Legal8.5 × 14215.9 × 355.6
Junior Legal8.0 × 5.0203.2 × 127
Ledger[5]17 × 11432 × 279
Tabloid11 × 17279 × 432

There is an additional paper size, to which the name "government-letter" was given by the IEEE Printer Working Group: the 8 in × 1012 in (203.2 mm × 266.7 mm) paper that is used in the United States and Canada for children's writing. It was prescribed by Herbert Hoover when he was Secretary of Commerce to be used for U.S. government forms, apparently to enable discounts from the purchase of paper for schools, but more likely due to the standard use of trimming books (after binding) and paper from the standard letter size paper to produce consistency and allow "bleed" printing. In later years, as photocopy machines proliferated, citizens wanted to make photocopies of the forms, but the machines did not generally have this size paper in their bins. Ronald Reagan therefore had the U.S. government switch to regular letter size (812 in × 11 in/215.9 mm × 279.4 mm).[2] The 8 in × 1012 in (203.2 mm × 266.7 mm) size is still commonly used in spiral-bound notebooks and the like, a result of trimming from the current letter dimensions.

U.S. paper sizes are currently standard in the United States, the Philippines and Chile. The latter two use U.S. "letter", but the Philippine and Chilean "legal" size is 812 in × 13 in (215.9 mm × 330.2 mm).[6] ISO sizes are available, but not widely used, in both the U.S. and the Philippines.

In Canada, U.S. paper sizes are a de facto standard. The government, however, uses a combination of ISO paper sizes, and CAN 2-9.60M "Paper Sizes for Correspondence" specifies P1 through P6 paper sizes, which are the U.S. paper sizes rounded to the nearest 5 mm.[7]

Mexico has adopted the ISO standard, but U.S. "letter" format is still the system in use throughout the country. It is virtually impossible to encounter ISO standard papers in day-to-day uses, with "Carta 216 mm × 279 mm" (letter), "Oficio 216 mm × 330 mm" (Government-Legal) and "Doble carta" (ledger/tabloid) being nearly universal. U.S. sizes are also widespread and in common use in Colombia.[8]

#### ANSI paper sizes

A size chart illustrating the ANSI sizes.

In 1996, the American National Standards Institute adopted ANSI/ASME Y14.1 which defined a regular series of paper sizes based upon the de facto standard 812 in × 11 in (215.9 mm × 279.4 mm) "letter" size which it assigned "ANSI A". This series also includes "ledger"/"tabloid" as "ANSI B". This series is somewhat similar to the ISO 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.

Namein × inmm × mmRatioAliasSimilar ISO A size
ANSI A8½ × 11216 × 2791.2941LetterA4
ANSI B17 × 11
11 × 17
432 × 279
279 × 432
1.5455Ledger[5]
Tabloid
A3
ANSI C17 × 22432 × 5591.2941A2
ANSI D22 × 34559 × 8641.5455A1
ANSI E34 × 44864 × 11181.2941A0

Other, larger sizes continuing the alphabetic series illustrated above exist, but it should be noted that 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 × 40 in or 711.2 mm × 1,016.0 mm) also exists, but is rarely encountered, as are G, H, ... N size drawings. G size is 2212 in (571.5 mm) high, but variable width up to 90 in (2,286 mm) in increments of 812 in (215.9 mm), 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 are slowly being phased out, due to widespread use of computer-aided design (CAD) and computer-aided manufacturing (CAM). Some visual arts fields also continue to use these paper formats for large-scale printouts, such as for displaying digitally painted character renderings at life-size as references for makeup artists and costume designers, or to provide an immersive landscape reference.

#### Architectural sizes

A size chart illustrating the Architectural sizes.

In addition to the ANSI system as listed above, there is a corresponding series of paper sizes used for architectural purposes. This series also shares the property that bisecting each size produces two of the size below.[9] It may be preferred by North American architects because the aspect ratios (4:3 and 3:2) are ratios of small integers, unlike their ANSI (or ISO) counterparts. Furthermore, the aspect ratio 4:3 matches the traditional aspect ratio for computer displays.[9] The architectural series, usually abbreviated "Arch", is shown below:

Namein × inmm × mmRatio
Arch A9 × 12229 × 3053:4
Arch B12 × 18305 × 4572:3
Arch C18 × 24457 × 6103:4
Arch D24 × 36610 × 9142:3
Arch E36 × 48914 × 12193:4
Arch E130 × 42762 × 10675:7
Arch E226 x 38660 x 96513:19
Arch E327 x 39686 x 9919:13

#### Other sizes

Namein × inmm × mmRatiodot x dot
Organizer J2.75 × 570 × 127~1.8142
Compact4.25 × 6.75108 × 1711.5833
Organizer L, Statement, Half Letter, Memo, Jepps*5.5 × 8.5140 × 2161.54
Executive, Monarch7.25 × 10.5184 × 267~1.4483
Government-Letter8 × 10.5203 × 2671.3125
Foolscap, Folio[5]8.27 × 13210 × 3301.625
Letter, Organizer M8.5 × 11216 × 279~1.2941
Fanfold 12x8.5, German Std Fanfold8.5 × 12216 × 3041.407612 × 864
Government-Legal, Folio8.5 × 13216 × 330~1.5294
Legal8.5 × 14216 × 3561.6481
Quarto9 × 11229 × 2791.2
US Std Fanfold11 × 14.875279 × 377~1.3513792 × 1071
Ledger, Tabloid, Organizer K, Bible11 × 17279 × 4321.54
Super-B13 × 19330 × 483~1.4615
Post15.5 × 19.5394 × 489~1.2581
Crown15 × 20381 × 5081.3
Large Post16.5 × 21419 × 5331.27
Demy17.5 × 22.5445 × 572~1.2857
Medium18 × 23457 × 5841.27
Royal20 × 25508 × 6351.25
Elephant23 × 28584 × 711~1.2174
Double Demy22.5 × 35572 × 8891.5
Quad Demy35 × 45889 × 1143~1.2857
Personal Organizers and Other Corporations[10][11]
CompanyNamePaper Size in x in (Various hole sizes)
FilofaxM2103 x 64 mm with 3 holes
Mini105 x 67 mm with 5 holes
Pocket120 x 81 mm with 6 holes
Personal171 x 95 mm with 6 holes
Slimline171 x 95 mm with 6 holes
A5210 x 148 mm with 6 holes
Deskfax (B5)250 × 176 mm with 9 holes
A4297 x 210 mm with 4 holes
Franklin Planner
Micro2⅝ x 4¼ (66.675 x 108 mm)
Pocket3½ x 6 (89 x 152 mm)
Compact4¼ x 6¾ (108 x 171 mm)
Classic5½ x 8½ (140 x 216 mm)
Monarch8½ x 11 (216 x 280 mm)
*Jeppesen Aeronautical ChartsJeppesen Chart5½ x 8½ (140 x 216 mm) 7 holes
FAA Aeronautical ChartsFAA Chart5½ x 8½ (140 x 216 mm) 3 holes at top
Namein × inmm × mmRatio
Index card3 × 576 × 1271.6
Index card4 × 6102 × 1521.5
Index card5 × 8127 × 2031.6
International business card *2⅛ × 3.3753.98 × 85.61.586
US business card2 × 3.551 × 891.75
Japanese business card~2.165 × ~3.58355 × 91~1.65
Hungarian business card~1.969 × ~3.54350 × 901.8

* This is the same size as the smallest rectangle containing a credit card. However, credit card size, as defined in ISO/IEC 7810, also specifies rounded corners and thickness.

Photographic paper sizes
Namein × inmm × mmRatio
2R2.5 × 3.564 × 891.4
-3 × 576 × 1271.6
LD, DSC3.5 × 4.6789 × 1191.3 (4:3)
3R, L3.5 × 589 × 127~1.4286
LW3.5 × 5.2589 × 1331.5 (3:2)
KGD4 × 5.33102 × 1361.3 (4:3)
4R, KG4 × 6102 × 1521.5 (3:2)
2LD, DSCW5 × 6.67127 × 1691.3 (4:3)
5R, 2L5 × 7127 × 1781.4
2LW5 × 7.5127 × 1901.5 (3:2)
6R6 × 8152 × 2031.3 (4:3)
8R, 6P8 × 10203 × 2541.25
S8R, 6PW8 × 12203 × 3051.5 (3:2)
11R11 × 14279 × 3561.27
A3+, Super B13 × 19330 × 483~1.46154
Postcard size limitations
DimensionMinimum (inch)Maximum (inch)
Height3.54.25
Width5.06.0
Thickness0.0070.016

### Tablet sizes

The sizes listed above are for paper sold loosely in reams. There are many sizes of tablets of paper, that is, sheets of paper bound at one edge, usually by a strip of plastic or hardened PVA adhesive. Often there is a pad of cardboard (also known as chipboard or greyboard) at the bottom of the stack. Such a tablet serves as a portable writing surface, and the sheets often have lines printed on them, usually in blue, to make writing in a line easier. An older means of binding is to have the sheets stapled to the cardboard along the top of the tablet; there is a line of perforated holes across every page just below the top edge from which any page may be torn off. Lastly, a pad of sheets each weakly stuck with adhesive to the sheet below, trademarked as "Post-It" or "Stick-Em" and available in various sizes, serve as a sort of tablet.

"Letter pads" are 812 by 11 inches (215.9 by 279.4 mm), while the term "legal pad" is often used by laymen to refer to pads of various sizes including those of 812 by 14 inches (215.9 by 355.6 mm). There are "steno pads" (used by stenographers) of 6 by 9 inches (152.4 by 228.6 mm).

In countries where the ISO sizes are standard, most notebooks and tablets are sized to ISO specifications (for example, most newsagents in Australia stock A4 and A3 tablets).

Traditionally, a number of different sizes were defined for large sheets of paper, and paper sizes were defined by the sheet name and the number of times it had been folded. Thus a full sheet of "royal" paper was 25 × 20 inches, and "royal octavo" was this size folded three times, so as to make eight sheets, and was thus 10 by 6¼ inches.

Imperial sizes were used in the United Kingdom and its territories. Some of the base sizes were as follows:

Namein × inmm × mmRatio
Emperor48 × 721219 × 18291.5
Antiquarian31 × 53787 × 13461.7097
Grand eagle28.75 × 42730 × 10671.4609
Double elephant26.75 × 40678 × 10161.4984
Atlas*26 × 34660 × 8641.3077
Colombier23.5 × 34.5597 × 8761.4681
Double demy22.5 × 35.5572 × 9021.5(7)
Imperial*22 × 30559 × 7621.3636
Double large post21 × 33533 × 8381.5713
Elephant*23 × 28584 × 7111.2174
Princess21.5 × 28546 × 7111.3023
Cartridge21 × 26533 × 6601.2381
Royal*20 × 25508 × 6351.25
Sheet, half post19.5 × 23.5495 × 5971.2051
Double post19 × 30.5483 × 7621.6052
Super royal19 × 27483 × 6861.4203
Medium*17.5 × 23470 × 5841.2425
Demy*17.5 × 22.5445 × 5721.2857
Large post16.5 × 21419 × 5331.(27)
Copy draught16 × 20406 × 5081.25
Large post15.5 × 20394 × 5081.2903
Post*15.5 × 19.25394 × 4891.2419
Crown*15 × 20381 × 5081.(3)
Pinched post14.75 × 18.5375 × 4701.2533
Foolscap*13.5 × 17343 × 4321.2593
Small foolscap13.25 × 16.5337 × 4191.2453
Brief13.5 × 16343 × 4061.1852
Pott12.5 × 15318 × 3811.2

* The sizes marked with an asterisk are still in use in the United States.

Traditional sizes for writing paper in the United Kingdom. These sizes are no longer commonly used since the UK switched to ISO sizes:[12]

Namein × in
Quarto11 × 9
Foolscap13 × 8
Imperial9 × 7
Kings8 × 6.5
Dukes7 × 5.5

The common divisions and their abbreviations include:

NameAbbr.FoldsLeavesPages
Foliofo, f124
Quarto4to248
Sexto, sixmo6to, 6mo3612
Octavo8vo3816
Duodecimo, twelvemo12mo41224
Sextodecimo, sixteenmo16mo41632

Foolscap folio is often referred to simply as "folio" or "foolscap". Similarly, "quarto" is more correctly "copy draught quarto".

Many of these sizes were only used for making books (see bookbinding), and would never have been offered for ordinary stationery purposes.[13]

### Demitab

The demitab or demi-tab (from the French "demi" or half tabloid) is 5.5 in × 8.5 in (140 mm × 216 mm), equal to one quarter of a sheet of 11 in × 17 in (279 mm × 432 mm) tabloid size paper. In actual circulation, the size 8 in × 10.5 in (203 mm × 267 mm) is common for a demitab.[14] Tabloid newspapers, which are "generally half the size of a broadsheet", also vary in size. To add to the lack of uniformity, broadsheets also vary in size.

Most industry standards express the direction of the grain last (e.g. 17×11 is short grain paper and 11×17 is long grain paper). See switching costs, network effects and standardization for possible reasons for differing regional adoption rates of the ISO standard sizes.

## Transitional paper sizes

### PA series

A transitional size called PA4 (210 mm × 280 mm/8.27 in × 11.02 in) was proposed for inclusion into the ISO 216 standard in 1975. It has the height of Canadian P4 paper (215 mm × 280 mm, about 8½ in × 11 in) and the width of international A4 paper (210 mm × 297 mm/8.27 in × 11.69 in). The table to the right, shows how this format can be generalized into an entire format series.

The PA formats did not end up in ISO 216, because the committee felt that the set of standardized paper formats should be kept to the minimum necessary. However, PA4 remains of practical use today. In landscape orientation, it has the same 4:3 aspect ratio as the displays of traditional TV sets, some computer displays and data projectors. PA4, with appropriate margins, is therefore a good choice as the format of presentation slides.

PA4 is also a useful compromise between A4 and US/Canadian Letter sizes. Hence it is used today by many international magazines, because it can be printed easily on equipment designed for either A4 or US Letter.

PA4-based series
Namemm × mmRatio
PA0840 × 11203:4
PA1560 × 8402:3
PA2420 × 5603:4
PA3280 × 4202:3
PA4210 × 2803:4
PA5140 × 2102:3
PA6105 × 1403:4
PA770 × 1052:3
PA852 × 70≈3:4
PA935 × 52≈2:3
PA1026 × 35≈3:4

### Antiquarian

Although the movement is towards the international standard metric paper sizes, on the way there from the traditional ones there has been at least one new size just a little larger than that used internationally. British architects and industrial designers once used a size called "Antiquarian" as listed above, but given in the New Metric Handbook (Tutt & Adler 1981) as 813 mm × 1,372 mm (32 in × 54 in) for board size. This is a little larger than the A0 size. So for a short time, a size called A0a (1,000 mm × 1,370 mm/39.4 in × 53.9 in) was used in Britain.

## Other metric sizes

Namemm × mmin × inNotes
DL99 × 2103.7 × 8.3common flyer 1/3 of an A4
DLE110 × 2204.3 × 8.7common envelope size as it fits an A4 sheet folded to 1/3 height.
F4210 × 3308.3 × 13.0common in Southeast Asia and Australia. Sometimes called "foolscap" there.
RA0841 × 118933.0125 × 46.75
RA1610 × 86024.0 × 33.9
RA2430 × 61016.9 × 24.0
RA3305 × 43012.0 × 16.9
RA4215 × 3058.5 × 12.0
SRA0900 × 128035.4 × 50.4
SRA1640 × 90025.2 × 35.4
SRA2450 × 64017.7 × 25.2
SRA3320 × 45012.6 × 17.7
SRA4225 × 3208.9 × 12.6
A3+329 × 48313.0 × 19.0

## Newspaper sizes

Newspapers have a separate set of sizes.

In a recent trend[15] many newspapers have been undergoing what is known as "web cut down", in which the publication is redesigned to print using a narrower (and less expensive) roll of paper. In extreme examples, some broadsheet papers are nearly as narrow as traditional tabloids.

## References

1. ^ "Lichtenberg’s letter to Johann Beckmann". Cl.cam.ac.uk. 2006-02-07. Retrieved 2012-01-30.
2. ^ a b American Forest and Paper Association. "Why is the standard paper size in the U.S. 8½" x 11"?". Retrieved 2009-08-04.
3. ^
4. ^ Fyffe, Charles (1969). Basic Copyfitting. London: Studio Vista. p. 74. ISBN 0-289-79705-5.
5. ^ a b c Adobe Systems Incorporated (February 9, 1996). "PostScript Printer Description File Format Specification". San Jose, California. p. 191. Retrieved 2008-03-06
6. ^ Rally de Leon. "Request for inclusion of Page Size 8.5"x13"". Retrieved 2008-08-11.
7. ^ Kuhn, Markus. "International standard paper sizes". Retrieved 2008-03-06.
8. ^ "Armada mil". Retrieved 2010-12-12.
9. ^ a b except for size Arch E1
10. ^
11. ^
12. ^ "Traditional sizes for writing paper in the United Kingdom". atsyn.com. Retrieved 2011-06-30.
13. ^
14. ^ Max Image Area. Horizon Publications.
15. ^ "Press web". Naa.org. Retrieved 2010-12-12.