The Series A is used for Standard Printing and Stationery. The Series B is used for Posters, Wall-Charts etc.
| A SERIES | mm X mm | Inch X Inch | B SERIES | mm X mm | Inch X Inch |
| A0 | 841 X 1189 | 33.11 X 46.81 | B0 | 1000 X 1414 | 39.37 X 55.67 |
| A1 | 594 X 841 | 23.39 X 33.11 | B1 | 707 X 1000 | 27.83X 39.37 |
| A2 | 420 X 594 | 16.54 X 23.39 | B2 | 500 X 707 | 19.68 X 27.83 |
| A3 | 297 X 420 | 11.69 X 16.54 | B3 | 353 X 500 | 13.90 X 19.68 |
| A4 | 210 X 297 | 8.27 X 11.69 | B4 | 250 X 353 | 9.84 X 13.90 |
| A5 | 148 X 210 | 5.83 X 8.27 | B5 | 176 X 250 | 6.93 X 9.84 |
| A6 | 105 X 148 | 4.13 X 5.83 | B6 | 125 X 176 | 4.92 X 6.93 |
| A7 | 74 X 105 | 2.91 X 4.13 | B7 | 88 X 125 | 3.46 X 4.92 |
| A8 | 52 X 74 | 2.05 X 2.91 | B8 | 62 X 88 | 2.44 X 3.46 |
| A9 | 37 X 52 | 1.46 X 2.05 | B9 | 44 X 62 | 1.73 X 2.44 |
| A10 | 26 X 37 | 1.02 X 1.46 | B10 | 31 X 44 | 1.22 X 1.73 |
| Area of A0 = 1 Square meter Width of An = 2^(-1/4-n/2) and Height = 2^(1/4-n/2)
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 X mm | Inch X Inch | Japanese B Series | mm X mm | Inch X Inch |
| C0 | 917X1297 | 36.10X51.06 | B0 | 1030 x 1456 | 40.55x57.32 |
| C1 | 648X917 | 25.53X36.10 | B1 | 728 x 1030 | 28.66x40.55= |
| C2 | 458X648 | 18.05X25.53 | B2 | 515x728 | 20.27x28.66 |
| C3 | 324X458 | 25.53X9.02 | B3 | 364x515 | 14.33x20.27 |
| C4 | 229X324 | 9.02X12.76 | B4 | 257x364 | 10.13x14.33 |
| C5 | 162X229 | 6.38X9.02 | B5 | 182x257 | 7.16x10.13 |
| C6 | 114X162 | 4.51X6.38 | B6 | 128x182 | 5.06x7.16 |
| C7 | 81X114 | 3.19X4.51 | B7 | 91x128 | 3.58x5.06 |
| C8 | 57X81 | 2.25X3.19 | B8 | 64x91 | 2.53x3.58 |
| C9 | 40X57 | 1.59X2.25 | B9 | 45x64 | 1.79x2.53 |
| C10 | 28X40 | 1.12X1.59 | B10 | 32x45 | 1.26x1.79 |
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 X mm | Inch X Inch | SRA SERIES | mm X mm | Inch X Inch |
| RA0 | 860X1220 | 33.86X48.03 | SRA0 | 900X1280 | 35.43 X 50.39 |
| RA1 | 610X860 | 24.01X33.86 | SRA1 | 640X900 | 25.19X35.43 |
| RA2 | 430X610 | 16.93X24.01 | SRA2 | 450X640 | 17.71X25.19 |
| RA3 | 305X430 | 12.00X16.93 | SRA3 | 320X450 | 12.59X17.71 |
| RA4 | 215X305 | 8.46X12.00 | SRA4 | 225X320 | 8.85X12.59 |
