There are two modern envelope size standards.
Contents |
International standard sizes
International standard ISO 269 defines several standard envelope sizes, which are designed for use with ISO 216 standard paper sizes:
| Format | Dimensions (mm) | Suitable for content format |
|---|---|---|
| DL | 110 × 220 | 1/3 A4 |
| C7/C6 | 81 x 162 | 1/3 A5 |
| C6 | 114 × 162 | A6 (or A4 folded in half twice) |
| C6/C5 | 114 × 229 | 1/3 A4 |
| C5 | 162 × 229 | A5 (or A4 folded in half once) |
| C4 | 229 × 324 | A4 |
| C3 | 324 × 458 | A3 |
| B6 | 125 × 176 | C6 |
| B5 | 176 × 250 | C5 |
| B4 | 250 × 353 | C4 |
| E3 | 280 × 400 | B4 |
The German standard DIN 678 defines a similar list of envelope formats.
North American sizes
There are dozens of sizes of envelopes available. Not all are used for posting mail, but for such things as former pay packets or putting a gift card or a key in. U.S. and Canadian, postal regulations differ from those of the rest of the world; although envelopes are still deliverable worldwide by the regulations of the Universal Postal Union, the sorting machines will not accept the international sizes. This is not as much a difference as usually thought, for the location of sending address and return address differ between Germany and France, for example. Most envelope sizes in this system have names, not designations. The designations under the system "A2", etc., do not correspond to ISO paper sizes.
| Format | Dimensions (in) | Dimensions (mm) | Ratio |
|---|---|---|---|
| A2 | 4 3/8 × 5 3/4 | 110.3 × 144.9 | 131% |
| A6 | 4 3/4 × 6 1/2 | 119.7 × 163.8 | 137% |
| A7 | 5 1/4 × 7 1/4 | 132.3 × 182.7 | 138% |
| No. 6¾ | 3 5/8 × 6 1/2 | 92.1 × 165.1 | 179% |
| No. 9 | 3 7/8 × 8 7/8 | 98.5 × 225.5 | 229% |
| No. 10 | 4 1/8 × 9 1/2 | 104.0 × 239.4 | 230% |
See also
External links
- American envelope sizes
- European envelope sizes and their uses
- My Design Primer - standard envelope sizes

