The Series A is used for Standard Printing and Stationery. The Series B is used for Posters, Wall-Charts etc.
Area of A0 = 1 Square meter  A0/A1 = AI/A2 = A2/A3 ………..A9/A10 = 2 Length = 1.414 * Width Width of An = 2^(-1/4-n/2) and Height = 2^(1/4-n/2) Area of B0 = 1.414 Square meter Width of Bn = 2^(-n/2) and Height = 2^(1/2-n/2) The C series is used for folders, post cards and envelopes. C series envelope is suitable to insert A series sizes. |
| C SERIES | mm × mm | Inch × Inch | Japanese B Series | mm × mm | Inch × Inch |
| C0 | 917×1297 | 36.10×51.06 | B0 | 1030 x 1456 | 40.55×57.32 |
| C1 | 648×917 | 25.53×36.10 | B1 | 728 x 1030 | 28.66×40.55 |
| C2 | 458×648 | 18.05×25.53 | B2 | 515×728 | 20.27×28.66 |
| C3 | 324×458 | 12.76×18.05 | B3 | 364×515 | 14.33×20.27 |
| C4 | 229×324 | 9.02×12.76 | B4 | 257×364 | 10.13×14.33 |
| C5 | 162×229 | 6.38×9.02 | B5 | 182×257 | 7.16×10.13 |
| C6 | 114×162 | 4.51×6.38 | B6 | 128×182 | 5.06×7.16 |
| C7 | 81×114 | 3.19×4.51 | B7 | 91×128 | 3.58×5.06 |
| C8 | 57×81 | 2.25×3.19 | B8 | 64×91 | 2.53×3.58 |
| C9 | 40×57 | 1.59×2.25 | B9 | 45×64 | 1.79×2.53 |
| C10 | 28×40 | 1.12×1.59 | B10 | 32×45 | 1.26×1.79 |
Width of Cn = 2^(-1/8-n/2) and Height = 2^(3/8-n/2)
The allowed tolerances are ±1.5 mm for dimensions up to 150 mm, ±2 mm for dimensions above 150 mm up to 600 mm, and ±3 mm for dimensions above 600 mm.
The A, B & C series are trimmed paper sizes. ISO also define format series RA and SRA for untrimmed raw paper, where SRA stands for ‘supplementary raw format A’. These formats are only slightly larger than the corresponding A series formats. Sheets in these formats are cut to the end format after binding. The ISO RA0 format has an area of 1.05 m2 and the ISO SRA0 format has an area of 1.15 m2. These formats also follow the sqrt(2)-ratio and half-area rule, but the dimensions of the start format have been rounded to the full centimeter. The common untrimmed paper formats that printers order from the paper manufacturers are
| RA SERIES | mm × mm | Inch × Inch | SRA SERIES | mm × mm | Inch × Inch |
| RA0 | 860×1220 | 33.86×48.03 | SRA0 | 900×1280 | 35.43 × 50.39 |
| RA1 | 610×860 | 24.01×33.86 | SRA1 | 640×900 | 25.19×35.43 |
| RA2 | 430×610 | 16.93×24.01 | SRA2 | 450×640 | 17.71×25.19 |
| RA3 | 305×430 | 12.00×16.93 | SRA3 | 320×450 | 12.59×17.71 |
| RA4 | 215×305 | 8.46×12.00 | SRA4 | 225×320 | 8.85×12.59 |
Common Application Examples:
| A0 & A1 | Technical drawings, posters |
| A1 & A2 | Flip charts |
| A2 & A3 | Drawings, diagrams, large tables |
| A4 | Letters, magazines, forms, catalogs, laser printer and copying machine output |
| A5 | Note pads |
| A6 | Postcards |
| B5, A5, B6 A6 | Books |
| C4, C5, C6 | Envelopes for A4 letters: unfolded (C4), folded once (C5), folded twice (C6) |
| B4 & A3 | Newspapers, supported by most copying machines in addition to A4 |
| B8 & A8 | Playing cards |
Japanese Paper Sizes
Japan has adopted the ISO series A sizes, but its series B sizes are slightly different. These sizes are sometimes called JIS B or JB sizes.
A JB0 sheet has an area of 1.5 square meters. The area of each size is the arithmetic average of the areas of the A series page with the same number and the A series page with the next higher number. So for example, the area of a JB4 page is the average of the area of an A4 sheet and an A5 sheet. (In the ISO B series, the area of each sheet is the geometric mean of the A sizes, that is, the square root of the sum of their areas.)
| JB SERIES | mm × mm | Inch × Inch | JB SERIES | mm × mm | Inch × Inch |
| JB0 | 1030×1456 | 40.55×57.32 | JB6 | 128×182 | 5.06×7.17 |
| JB1 | 728×1030 | 28.66×40.55 | JB7 | 91×128 | 3.59×5.06 |
| JB2 | 515×728 | 20.27×28.66 | JB8 | 64×91 | 2.53×3.59 |
| JB3 | 364×515 | 14.33×20.27 | JB9 | 45×64 | 1.8×2.53 |
| JB4 | 257×364 | 10.13×14.33 | JB10 | 32×45 | 1.27×1.8 |
| JB5 | 182×257 | 7.17×10.13 |
Japanese Traditional paper sizes
shiroku-ban
base size: 788 mm by 1091 mm (26 sun* × 36 sun)
4 × 6/4 264 by 379 ( × 12.5 sun)
4 × 6/5 191 by 259 (printing on half sheets)
4 × 6/5 189 by 262
kiku-ban
base size: 639 mm × 939 mm (21 sun × 31 sun)
Kiku 4, 227 mm × 306 mm
Kiku 5, 151 mm × 227 mm
* sun was a unit of length used in Japan and is equal to about 3.03 cm or 1.193 inches
The United States, Canada, and in part Mexico, are today the only industrialized nations in which the ISO standard paper sizes are not yet widely used.
| US Engineering | mm × mm | Inch × Inch | US Architecture | mm × mm | Inch × Inch |
| ANSI A | 215.9×279.4 | 8.5×11 | ARCH A | 228.6×304.8 | 9×12 |
| ANSI B | 279.4×431.8 | 11×17 | ARCH B | 304.8×457.2 | 12×18 |
| ANSI C | 431.8×558.8 | 17×22 | ARCH C | 457.2×509.6 | 18×24 |
| ANSI D | 588.8×863,6 | 22×34 | ARCH D | 609.6×914.4 | 24×36 |
| ANSI E | 863.6×1117.6 | 34×44 | ARCH E | 914.4×1219.2 | 36×48 |
| ARCH E1 | 762×1067 | 30×32 | |||
| ARCH E2 | 660×965 | 26×38 | |||
| ARCH E3 | 686×991 | 27×39 |
http://www.cl.cam.ac.uk/~mgk25/iso-paper.html (A very good reference on paper sizes)
