Paper size

There have been many standard sizes of paper at different times and in different countries.

Table of contents

1 International paper sizes
2 Traditional paper sizes
3 Current U.S. paper sizes
4 External links

International paper sizes

The international standard is ISO 216, which defines amongst others, A4. ISO paper sizes are all based on a single aspect ratio of the square root of two, 1:1.4142. The largest standard size, A0, has an area of 1 m². A1 is formed by cutting a piece of A0 in half, which retains the aspect ratio. This particular measurement system was chosen in order 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 text, photograph or whatever. Office photocopiers in countries that use ISO 216 paper often have one tray filled with A4 and one filled with A3. A simple method is usually provided (e.g. one button press) to enlarge A4 to A3 or reduce A3 to A4. Thus an A4 brochure when open is A3 and can be placed on the copier and either printed directly onto the A3 paper or reduced to A4.

The ISO B series is a scaling of the A series; B1 is half way between A0 and A1 in area. The C series is half way between the A and B series of the same number; for instance, C0 is half way between A0 and B0. This way, C0 is slightly larger than A0, and B0 slightly larger than C0. This was intended to allow one to fit inside an envelope of the other. For instance, a letter written on A4 paper, the standard for this role, fits inside a C4 envelope. A C4 envelope can fit inside a B4 envelope.

The scalability also means that less paper (and hence money) is wasted by printing companies.

ISO 216 does not define any sizes larger than A0 and B0, but the German standard DIN 476 puts a factor in front of these (so 2A0 is twice the size of A0, 4A0 is four time A0, etc.).

International standard paper sizes are now used in all countries except the United States, Canada, and some Latin American countries.

ISO/DIN paper sizes (in mm)
A- B- C- D- E-
-0 841 × 1189 1000 × 1414 917 × 1297
-1 594 × 841 707 × 1000 648 × 917 545 × 771
-2 420 × 594 500 × 707 458 × 648 385 × 545
-3 297 × 420 353 × 500 324 × 458 272 × 385 400 × 560
-4 210 × 297 250 × 353 229 × 324 192 × 272 280 × 400
-5 148 × 210 176 × 250 162 × 229 136 × 192 200 × 280
-6 105 × 148 125 × 176 114 × 162 96 × 136 140 × 200
-7 74 × 105 88 × 125 81 × 114 68 × 96
-8 52 × 74 62 × 88 57 × 81
-9 37 × 52 44 × 62 40 × 57
-10 26 × 37 31 × 44 28 × 40

Traditional 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 20 x 12.5 inches, and "Royal Octavo" was this size folded 3 times, so as to make eight sheets, and was thus 10" by 6.25 inches.

Some of the base sizes commonly used in the US were as follows (all in inches):

Atlas: 34 x 26

Imperial: 30 x 22

Elephant: 28 x 23

Royal: 25 x 20

Medium: 23 x 18

Demy: 22½ x 17½

Crown: (also known as Post): 20 x 15

Foolscap: 17 x 13½"

The sizes used in the UK were similar but in a few cases differed in detail.

The common divisions and their abbreviations include:

Folio, fo/f: 1 fold, into 2 pages

Quarto, 4to: 2 folds, into 4 pages

Sexto or Sixmo, 6to/6mo: 3 folds, into 6 pages

Octavo, 8vo: 3 folds, into 8 pages

Duodecimo or Twelvemo, 12mo: 4 folds, into 12 pages

Sextodecimo or Sixteenmo, 16mo: 4 folds, into 16 pages

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

Current U.S. paper sizes

Current standard sizes of U.S. paper are a subset of the traditional sizes referred to above. Letter, legal, and foolscap are by far the most commonly used for everyday activities.

Name	Size (inches)	Size (mm)	Aspect ratio
Quarto	10 × 8	254.0 × 203.2	1.25
Foolscap	13 × 8	330.2 × 203.2	1.63
Letter	8½ × 11	215.9 × 279.4	1.29
Legal	8½ × 14	215.9 × 355.6	1.65
Ledger / Tabloid	11 × 17	279.4 × 431.8	1.55
Executive	7¼ × 10½	184.15 × 266.7	1.45
Post	15½ × 19¼	393.7 × 488.95	1.24
Crown	15 × 20	381.0 × 508.0	1.33
Large post	16½ × 21	419.1 × 533.4	1.28
Demy	17½ × 22½	444.5 × 571.5	1.29
Medium	18 × 23	457.2 × 584.2	1.28
Royal	20 × 25	508.0 × 635.0	1.25
Elephant	23 × 28	584.2 × 711.2	1.22
Double Demy	23½ × 35	596.9 × 889.0	1.49
Quad Demy	35 × 45	889.0 × 1143.0	1.29
A	8½ × 11	215.9 × 279.4	1.29
B	11 × 17	279.4 × 431.8	1.55
C	17 × 22	431.8 × 558.8	1.29
D	22 × 34	558.8 × 863.6	1.55
E	34 × 44	863.6 × 1117.6	1.29