PAPER SIZE

There have been many standard 'sizes of paper' at different times and in different countries, but today there are two major systems in use: the international standard (A4 and its siblings), and the North American sizes.

Contents

The international standard: ISO 216

German extensions

Swedish extensions

Japanese B-series variant

North American paper sizes

Loose sizes

ANSI paper sizes

Architectural sizes

Other sizes

Tablet sizes

Traditional inch-based paper sizes

Transitional paper sizes

PA series

Antiquarian

F4

Other metric sizes

See also

References

External links

The international standard: ISO 216

Main articles: ISO 216

The international paper size standard, ISO 216, is based on the German DIN 476 standard for paper sizes. Using the metric system, the base format is a sheet of paper measuring 1 m² in area (A0 paper size). Successive paper sizes in the series A1, A2, A3, etc., are defined by halving the preceding paper size parallel to its shorter side. The most frequently used paper size is A4 (210 × 297 mm).
This standard has been adopted by all countries in the world except the United States and Canada. In Mexico, Colombia and the Philippines, despite the ISO standard having been officially adopted, the U.S. "letter" format is still in common use.
ISO paper sizes are all based on a single aspect ratio of the square root of two, or approximately 1:1.4142. The advantages of basing a paper size upon this ratio were already noted in 1786 by the German scientist Georg Lichtenberg (in a letter to Johann Beckmann): if a sheet with aspect ratio √2 is horizontally divided into two equal halves, then the halves will again have aspect ratio √2. In the beginning of the twentieth 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" in everyday use in Germany.
The DIN 476 standard spread quickly to other countries, and before the outbreak of World War II it had been adopted by the following countries:

★ Belgium (1924)

★ Netherlands (1925)

★ Norway (1926)

★ Switzerland (1929)

★ Sweden (1930)

★ Soviet Union (1934)

★ Hungary (1938)

★ Italy (1939)
During the war it was adopted by Uruguay (1942), Argentina (1943) and Brazil (1943); and directly afterwards the standard continued to spread to other countries:

★ Spain (1947)

★ Austria (1948)

★ Romania (1949)

★ Japan (1951)

★ Denmark (1953)

★ Czechoslovakia (1953)

★ Iran (1948)

★ Israel (1954)

★ Portugal (1954)

★ Yugoslavia (1956)

★ India (1957)

★ Poland (1957)

★ United Kingdom (1959)

★ Ireland (1959)

★ Venezuela (1962)

★ New Zealand (1963)

★ Iceland (1964)

★ Mexico (1965)

★ South Africa (1966)

★ France (1967)

★ Peru (1967)

★ Turkey (1967)

★ Chile (1968)

★ Greece (1970)

★ Zimbabwe (1970)

★ Singapore (1970)

★ Bangladesh (1972)

★ Thailand (1973)

★ Barbados (1973)

★ Australia (1974)

★ Ecuador (1974)

★ Colombia (1975)

★ Kuwait (1975)
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, and today only the U.S. and Canada have not adopted the system.
The largest standard size, A0, has an area of 1 m². The length of the long side of the sheet in metres is the 4th root of 2—approximately 1.189 metres. The short side is the reciprocal of this number, approximately 0.841 metres. A1 is formed by cutting a piece of A0 into two equal area rectangles. Because of the choice of lengths, the aspect ratio is the same for A1 as for A0 (as it is for A2, A3, etc). This particular measurement system was chosen to allow folding of one standard size into another, which cannot be accomplished with traditional paper sizes.
Brochures are made by using material at the next size up i.e. material at A3 is folded to make A4 brochures. Similarly, material at A4 is folded to make A5 brochures.
It also allows scaling without loss of image from one size to another. Thus an A4 page can be enlarged to A3 and retain the exact proportions of the original document. Office photocopiers in countries that use ISO 216 paper often have one tray filled with A4 and another filled with A3. A simple method is usually provided (e.g. one button press) to enlarge A4 to A3 or reduce A3 to A4. This also allows two sheets of A4 (or any other size) to be scaled down and fit exactly 1 sheet without any cutoff or margins.

There is also a much 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 0.71 m² ($sqrt\{2\}^\{-1\}$). As a result, B0 has one side 1-metre long, and other sizes in the B series have one side that is a half, quarter or eighth of a metre. 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 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 sturdier B4 envelope.
The scalability also means that less paper (and hence money) is wasted by printing companies.

ISO paper sizes (plus rounded inch values)

Format	A series		B series		C series
Size	mm × mm	in × in	mm × mm	in × in	mm × mm	in × in
-0	841 × 1189	33.1 × 46.8	1000 × 1414	39.4 × 55.7	917 × 1297	36.1 × 51.1
-1	594 × 841	23.4 × 33.1	707 × 1000	27.8 × 39.4	648 × 917	25.5 × 36.1
-2	420 × 594	16.5 × 23.4	500 × 707	19.7 × 27.8	458 × 648	18.0 × 25.5
-3	297 × 420	11.7 × 16.5	353 × 500	13.9 × 19.7	324 × 458	12.8 × 18.0
-4	210 × 297	8.3 × 11.7	250 × 353	9.8 × 13.9	229 × 324	9.0 × 12.8
-5	148 × 210	5.8 × 8.3	176 × 250	6.9 × 9.8	162 × 229	6.4 × 9.0
-6	105 × 148	4.1 × 5.8	125 × 176	4.9 × 6.9	114 × 162	4.5 × 6.4
-7	74 × 105	2.9 × 4.1	88 × 125	3.5 × 4.9	81 × 114	3.2 × 4.5
-8	52 × 74	2.0 × 2.9	62 × 88	2.4 × 3.5	57 × 81	2.2 × 3.2
-9	37 × 52	1.5 × 2.0	44 × 62	1.7 × 2.4	40 × 57	1.6 × 2.2
-10	26 × 37	1.0 × 1.5	31 × 44	1.2 × 1.7	28 × 40	1.1 × 1.6

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

Name	mm × mm	in × in
4A0	1682 × 2378	66.2 × 93.6
2A0	1189 × 1682	46.8 × 66.2

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

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 2^1/16 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 and E5 are popular in Sweden for printing dissertations [1], but the other formats have not turned out to be particularly useful in practice and they have not caught on 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, 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 and most photocopiers are loaded with at least A4 and B4 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.

ISO paper sizes (plus rounded inch values)

Format	B series		Shiroku ban		Kiku
Size	mm × mm	in × in	mm × mm	in × in	mm × mm	in × in
-0	1030 × 1456	40.6 × 57.3
-1	728 × 1030	28.7 × 40.6
-2	515 × 728	20.3 × 28.7
-3	364 × 515	14.3 × 20.3
-4	257 × 364	10.1 × 14.3	264 × 379	10.4 × 14.9	227 × 306	8.9 × 12.0
-5	182 × 257	7.2 × 10.1	189 × 262	7.4 × 10.3	151 × 227	5.9 × 8.9
-6	128 × 182	5.0 × 7.2	189 × 262	7.4 × 10.3
-7	91 × 128	3.6 × 5.0	127 × 188	5.0 × 7.4
-8	64 × 91	2.5 × 3.6
-9	45 × 64	1.8 × 2.5
-10	32 × 45	1.3 × 1.8
-11	22 × 32	0.9 × 1.3
-12	16 × 22	0.6 × 0.9

North American paper sizes

Loose sizes

Current standard sizes of U.S. paper are a subset of the traditional sizes referred to below. "Letter", "legal", and "ledger"/"tabloid" are by far the most commonly used of these for everyday activities. The origin of the exact dimensions of "letter" size paper (8.5" × 11", 216 mm × 279 mm) are lost in tradition and not well documented. The author of the American Forest and Paper Association website 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.
There is an additional paper size, to which the name "government-letter" was given by the IEEE Printer Working Group: the 8" × 10.5" paper that is used in America 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. 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 (8.5" × 11"). The 8" × 10.5" size is still commonly used in spiral-bound notebooks and the like.
An alternative explanation in the past for the difference between "government size" (as government-letter size was referred to at the time) and letter size paper was that the slightly smaller sheet used less paper, and therefore saved the government money in both paper and filing space. However, when Reagan prescribed the change to letter size, it was commonly stated that U.S. paper manufacturers had standardized their production lines for letter size, and were meeting government orders by trimming ½" each from two sides of letter-size stock; thus the government was allegedly paying more for its smaller paper size before Reagan abolished it. The different paper size also reportedly restricted the government's ability to take advantage of modular office furniture designs, common in the 1980s, whose cabinets were designed for letter size paper.
U.S. paper sizes are currently standard in the United States and the Philippines. The latter uses U.S. "letter," but the Philippine "legal" size is 8.5" × 13". 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 half-centimeter [3].
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 21.6 x 27.9 cm" (letter), "Oficio 21.6 x 34 cm" (legal) and "Doble carta" (ledger/tabloid) being nearly universal. U.S. sizes are also widespread and
in common use in Brazil, Chile [4], Colombia [5], and Costa Rica [6].
See switching costs, network effects and standardization for possible reasons for differing regional adoption rates of the ISO standard sizes.

ANSI paper 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 8.5" × 11" "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.

Name	in × in	mm × mm	Ratio	Alias	Similar ISO size
ANSI A	8½ × 11	279 × 216	1.2941	Letter	A4
ANSI B	11 × 17	432 × 279	1.5455	Ledger, Tabloid	A3
ANSI C	17 × 22	559 × 432	1.2941		A2
ANSI D	22 × 34	864 × 559	1.5455		A1
ANSI E	34 × 44	1118 × 864	1.2941		A0

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" × 40") also exists, but is rarely encountered, as are G, H, … N size drawings. G size is 22.5" high, but variable width up to 90 inches in increments of 8.5", 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).

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. This series is likely preferred by architects due to the fact that the aspect ratios (4:3 and 3:2) are ratios of small numbers, unlike their ANSI (or ISO) counterparts. Furthermore, the aspect ratio 4:3 matches the traditional aspect ratio for computer displays. The architectural series, usually abbreviated "Arch", is shown below:

Name	in × in	mm × mm	Ratio
Arch A	12 × 9	305 × 229	4:3
Arch B	18 × 12	457 × 305	3:2
Arch C	24 × 18	610 × 457	4:3
Arch D	36 × 24	914 × 610	3:2
Arch E	48 × 36	1219 × 914	4:3
Arch E1	42 × 30	1067 × 762	7:5

Other sizes

Name	in × in	mm × mm	Ratio
Statement, Half Letter	5½ × 8½	140 × 216	1.5455
Quarto	8 × 10	203 × 254	1.25
Executive, Monarch	7¼ × 10½	184 × 267	1.4483
Government-Letter	8 × 10½	203 × 267	1.3125
Letter	8½ × 11	216 × 279	1.2941
Foolscap, Folio	8 × 13	203 × 330	1.625
Government-Legal	8½ × 13	216 × 330	1.52(7)
Legal	8½ × 14	216 × 356	1.6471
Ledger, Tabloid	11 × 17	279 × 432	1.(54)
Super-B	8½ × 19	330 × 483	2.2353
Post	15½ × 19½	394 × 489	1.2419
Crown	15 × 20	381 × 508	1.(3)
Large Post	16½ × 21	419 × 533	1.(27)
Demy	17½ × 22½	445 × 572	1.2857
Medium	18 × 23	457 × 584	1.(27)
Broadsheet	18 × 24	457 × 610	1.(3)
Royal	20 × 25	508 × 635	1.25
Elephant	23 × 28	584 × 711	1.2174
Double Demy	22½ × 35	572 × 889	1.(5)
Quad Demy	35 × 45	889 × 1143	1.2857

Index and business cards

Name	in × in	mm × mm	Ratio
Index card	3 × 5	76 × 127	1.(6)
Index card	4 × 6	102 × 152	1.5
Index card	5 × 8	127 × 203	1.6
International business card	2⅛ × 3.37	53.98 × 85.6	1.586
US business card	2 × 3½	51 × 89	1.75

Photographs

in × in	mm × mm	Ratio
3 × 5	76 × 127	1.(6)
4 × 6	102 × 152	1.5
5 × 7	127 × 178	1.4
8 × 10	203 × 254	1.25

Tablet sizes

The sizes listed above are for paper sold loosely in reams. There are a large number of sizes of tablets of paper, that is, sheets of paper kept from flying around by being 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 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, trade-marked as "Post-It" or "Stick-Em" and available in various sizes, serve as a sort of tablet.
The significance of taking separate note of these sizes is that their contents are just as likely to be photocopied and enlarged, of course onto loose paper, as are the more standardized international sizes of paper.
"Letter pads" are of course 8½ by 11 inches, while the term "Legal pad" is often used by laymen to refer to pads of various sizes including those of 8½ by 14 inches. There are "Steno pads" (used by stenographers) of 6 by 9 inches. Similar pads exist for pre-school children of twice and four times this size, 9 by 12 inches and 12 by 18 inches, which are ruled with the lines going the long way across the paper. This provides ample writing area for young children who have not yet developed fine motor control. For this latter use, there are also pads of 10¾ by 13½ inches.
For varied commercial purposes, all sorts of sizes have been recently observed: 4 by 5½ inches; 5 by 8 inches; 5⅜ by 8¼ inches; 6 by 9½ inches; 7¼ by 9½ inches; and 7¾ by 9⅞ inches.
The only "metric" paper in the shops where this observation was taken are a few Chinese-made "composition books" for children which are 190 mm by 247 mm, a slight modification from the 7¾ by 9¾ inch ones. But the holes in the sheets of any of these tablets fit American-standard binders.
Of course, 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).

Traditional inch-based paper sizes

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:

Name	in × in	mm × mm	Ratio
Emperor	48 × 72	1219 × 1829	1.5
Antiquarian	31 × 53	787 × 1346	1.7097
Grand eagle	28¾ × 42	730 × 1067	1.4609
Double elephant	26¾ × 40	678 × 1016	1.4984
Atlas ★	26 × 34	660 × 864	1.3077
Colombier	23½ × 34½	597 × 876	1.4681
Double demy	22½ × 35½	572 × 902	1.5(7)
Imperial ★	22 × 30	559 × 762	1.3636
Double large post	21 × 33	533 × 838	1.5713
Elephant ★	23 × 28	584 × 711	1.2174
Princess	21½ × 28	546 × 711	1.3023
Cartridge	21 × 26	533 × 660	1.2381
Royal ★	20 × 25	508 × 635	1.25
Sheet, half post	19½ × 23½	495 × 597	1.2051
Double post	19 × 30½	483 × 762	1.6052
Super royal	19 × 27	483 × 686	1.4203
Medium ★	17½ × 23	470 × 584	1.2425
Demy ★	17½ × 22½	445 × 572	1.2857
Large post	16½ × 21	419 × 533	1.(27)
Copy draught	16 × 20	406 × 508	1.25
Large post	15½ × 20	394 × 508	1.2903
Post ★	15½ × 19¼	394 × 489	1.2419
Crown ★	15 × 20	381 × 508	1.(3)
Pinched post	14¾ × 18½	375 × 470	1.2533
Foolscap ★	13½ × 17	343 × 432	1.2593
Small foolscap	13¼ × 16½	337 × 419	1.2453
Brief	13½ × 16	343 × 406	1.1852
Pott	12½ × 15	318 × 381	1.2

★ The sizes marked with an asterisk are still in use in the United States.
The common divisions and their abbreviations include:

Name	Abbr.	Folds	Leaves	Pages
Folio	fo, f	1	2	4
Quarto	4to	2	4	8
Sexto, sixmo	6to, 6mo	3	6	12
Octavo	8vo	3	8	16
Duodecimo, twelvemo	12mo	4	12	24
Sextodecimo, sixteenmo	16mo	4	16	32

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.

Transitional paper sizes

PA series

PA4-based series

Name	mm × mm	Ratio
PA0	840 × 1120	3:4
PA1	560 × 840	2:3
PA2	420 × 560	3:4
PA3	280 × 420	2:3
PA4	210 × 280	3:4
PA5	140 × 210	2:3
PA6	105 × 140	3:4
PA7	70 × 105	2:3
PA8	52 × 70	≈3:4
PA9	35 × 52	≈2:3
PA10	26 × 35	≈3:4

A transitional size called 'PA4' (210 mm × 280 mm, 8¼ in × 11 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). 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, most computers and data projectors. PA4 is therefore a good choice as the format of computer presentation slides. At the same time, PA4 is the largest format that fits on both A4 and U.S./Canadian "Letter" paper without resizing.
PA4 is used today by many international magazines, because it can be printed easily on equipment designed for either A4 or U.S. "Letter".

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 × 1372 mm. This is a little larger than the A0 size. So for a short time, a size called A0a (1000 mm × 1370 mm) was used in Britain.

F4

F4 (210 mm × 330 mm) is common in Southeast Asia and Australia, and is sometimes called "foolscap". It has the same width as A4, but is longer.

Other metric sizes

Name	mm × mm	in × in
DL	110 × 220	4.3 × 8.7
F4	210 × 330	8.3 × 13.0
RA0	860 × 1220	33.9 × 48.0
RA1	610 × 860	24.0 × 33.9
RA2	430 × 610	16.9 × 24.0
RA3	305 × 430	12.0 × 16.9
RA4	215 × 305	8.5 × 12.0
SRA0	900 × 1280	35.4 × 50.4
SRA1	640 × 900	25.2 × 35.4
SRA2	450 × 640	17.7 × 25.2
SRA3	320 × 450	12.6 × 17.7
SRA4	225 × 320	8.9 × 12.6
A3+	305 × 457	12.0 × 18.0

See also

★ Paper density

★
★ Grammage

★
★ Basis weight

★ Photographic printing — standard photographic print sizes

★ Punchhole — filing holes

★ Envelope size

★ Index card

★ Book size

★ Bookbinding

References

# International standard ISO 216, Writing paper and certain classes of printed matter — Trimmed sizes — A and B series. International Organization for Standardization, Geneva, 1975.
# International standard ISO 217: Paper — Untrimmed sizes — Designation and tolerances for primary and supplementary ranges, and indication of machine direction. International Organization for Standardization, Geneva, 1995.
# M. Kuhn: International standard paper sizes. Web page, Computer Laboratory, University of Cambridge, 1996–2006.
# Max Helbig, Winfried Hennig: DIN-Format A4 – Ein Erfolgssystem in Gefahr. Beuth-Kommentare, Beuth Verlag, Berlin, 1998. ISBN 3-410-11878-0
# Arthur D. Dunn: Notes on the standardization of paper sizes. Ottawa, Canada, 54 pages, 1972.
# American Forest and Paper Association — FAQ: Why is the standard paper size in the U.S. 8 ½" × 11"?

External links

★ Papersize Cheatsheet

★ Page listing conversion tables for paper weights

★ Web page on traditional paper sizes used in books, with reference tables

★ [ftp://ftp.pwg.org/pub/pwg/standards/pwg5101.1.pdf IEEE-ISTO 5101.1-2002 "The Printer Working Group Standard for Media Standardized Names" (PDF)]

★ American paper sizes

★ Japanese and international paper size

★ Georg C. Lichtenberg (25 Oct. 1786) Letter to Johann Bergmann.

★ Paper Weight & Size -- When is 80# NOT 80#?

★ A4 versus US Letter, by Brian Forte

★ Markus Kuhn's excellent discussion, which may be freely reprinted.