Paper size series
ISO C series (envelopes): Dimensions Chart
ISO 269 C sizes are envelope formats designed to hold the matching A sheet: a C4 envelope holds an unfolded A4 sheet, C5 an A4 folded once.
Sizes to scale
| Size | Millimetres | Inches | Pixels @ 300 dpi | Typical use |
|---|---|---|---|---|
| C0 envelope | 917 x 1297 mm | 36.1 x 51.06 in | 10,831 x 15,319 | — |
| C1 envelope | 648 x 917 mm | 25.51 x 36.1 in | 7,654 x 10,831 | — |
| C2 envelope | 458 x 648 mm | 18.03 x 25.51 in | 5,409 x 7,654 | — |
| C3 envelope | 324 x 458 mm | 12.76 x 18.03 in | 3,827 x 5,409 | Envelope for unfolded A3. |
| C4 envelope | 229 x 324 mm | 9.02 x 12.76 in | 2,705 x 3,827 | Envelope for unfolded A4 sheets and catalogues. |
| C5 envelope | 162 x 229 mm | 6.38 x 9.02 in | 1,913 x 2,705 | Envelope for A4 folded once, or A5 unfolded. |
| C6 envelope | 114 x 162 mm | 4.49 x 6.38 in | 1,346 x 1,913 | Envelope for A4 folded twice, or A6 cards. |
| C7 envelope | 81 x 114 mm | 3.19 x 4.49 in | 957 x 1,346 | Envelope for A7 cards. |
| C8 envelope | 57 x 81 mm | 2.24 x 3.19 in | 673 x 957 | — |
| C9 envelope | 40 x 57 mm | 1.57 x 2.24 in | 472 x 673 | — |
| C10 envelope | 28 x 40 mm | 1.1 x 1.57 in | 331 x 472 | — |
| DL envelope | 110 x 220 mm | 4.33 x 8.66 in | 1,299 x 2,598 | Holds A4 folded in thirds — the standard European letter envelope. |
| C6/C5 envelope | 114 x 229 mm | 4.49 x 9.02 in | 1,346 x 2,705 | Long envelope for A4 folded in thirds. |
| 1/3 A4 | 99 x 210 mm | 3.9 x 8.27 in | 1,169 x 2,480 | — |
| Italian envelope | 110 x 230 mm | 4.33 x 9.06 in | 1,299 x 2,717 | — |
| C7/C6 envelope | 81 x 162 mm | 3.19 x 6.38 in | 957 x 1,913 | — |
| B6/C4 envelope | 125 x 324 mm | 4.92 x 12.76 in | 1,476 x 3,827 | — |
| Invite envelope | 220 x 220 mm | 8.66 x 8.66 in | 2,598 x 2,598 | — |
| DIN E4 envelope | 280 x 400 mm | 11.02 x 15.75 in | 3,307 x 4,724 | — |