Paper Sizes and Folds

Paper Sizes

International standards ISO 216 and ISO 269 specify 3 different paper sizes

A Series

This is the most common and well known series of paper sizes, the largest of which is the A0 which has an area of one square metre. The series is defined in the following diagram were A1 is half the size of A0, A2 is half the size of A1 and so on. 300px-a_size_illustration

A0	841 × 1189
A1	594 × 841
A2	420 × 594
A3	297 × 420
A4	210 × 297
A5	148 × 210
A6	105 × 148
A7	74 × 105
A8	52 × 74
A9	37 × 52
A10	26 × 37

(note all sizes are in mm)

B Series

B0	1000 × 1414
B1	707 × 1000
B2	500 × 707
B3	353 × 500
B4	250 × 353
B5	176 × 250
B6	125 × 176
B7	88 × 125
B8	62 × 88
B9	44 × 62
B10	31 × 44

This series is secondary to the A series. The sizes are geometric means between sizes in the A series. For example, the width of A1 is 594 mm, of A2, 420 mm. The width of B2 is set at = 499.47, which is rounded to 500 mm.

(note all sizes are in mm)

C Series

C0	917 × 1297
C1	648 × 917
C2	458 × 648
C3	324 × 458
C4	229 × 324
C5	162 × 229
C6	114 × 162
C7/6	81 × 162
C7	81 × 114
C8	57 × 81
C9	40 × 57
C10	28 × 40
DL	110 × 220

The C series formats are geometric means between the B series format with the same number and the A series format with the same number, e.g. C2 is the geometric mean between B2 and A2. The C series formats are used mainly for envelopes. An A4 page will fit into a C4 envelope. If you fold the A4 page so that it is A5 in size, it will fit in a C5 envelope and so on.

(note all sizes are in mm)

applicability

Prior to the adoption of ISO 216, many different paper formats were used internationally. These formats did not fit into a coherent system and were defined in terms of non-metric units. The ISO 216 formats are organized around the ratio 1:√2; two sheets next to each other together have the same ratio, sideways. This simplifies copying two A4 sheets in reduced size on one, and copying an A4 sheet in magnified size on an A3 sheet or copying half an A4 sheet in magnified size on an A4 sheet. The principal countries not generally using the ISO paper sizes are the United States of America and Canada, which use the Letter, Legal, and Executive system. (Canada uses a P-series of sizes, which are the American paper sizes rounded to metric dimensions.)

paper folds