International Standard Paper Sizes

A Series Formats		B Series Formats		C Series Formats
4A0	1682 × 2378	–	–	–	–
2A0	1189 × 1682	–	–	–	–
A0	841 × 1189	B0	1000 × 1414	C0	917 × 1297
A1	594 × 841	B1	707 × 1000	C1	648 × 917
A2	420 × 594	B2	500 × 707	C2	458 × 648
A3	297 × 420	B3	353 × 500	C3	324 × 458
A4	210 × 297	B4	250 × 353	C4	229 × 324
A5	148 × 210	B5	176 × 250	C5	162 × 229
A6	105 × 148	B6	125 × 176	C6	114 × 162
A7	74 × 105	B7	88 × 125	C7	81 × 114
A8	52 × 74	B8	62 × 88	C8	57 × 81
A9	37 × 52	B9	44 × 62	C9	40 × 57
A10	26 × 37	B10	31 × 44	C10	28 × 40

Application examples The ISO standard paper size system offers a wide range of sizes. Among the formats, A4 is the most important size for daily use. Here are some of the main applications:

Sizes	Applicable To
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

Envelope formats For postal purposes, ISO 269 and DIN 678 define the following envelope formats:

Format	Size [mm]	Content Format
C6	114 × 162	A4 folded twice = A6
DL	110 × 220	A4 folded twice = 1/3 A4
C6/C5	114 × 229	A4 folded twice = 1/3 A4
C5	162 × 229	A4 folded once = A5
C4	229 × 324	A4
C3	324 × 458	A3
B6	125 × 176	C6 envelope
B5	176 × 250	C5 envelope
B4	250 × 353	C4 envelope
E4	280 × 400	B4

A size chart illustrating the ISO A series and a comparison with American letter and legal formats.