International Envelope Paper Sizes
Further Information
The standard envelope sizes are defined by the international standard ISO 269. They are generally designed to be used with paper sizes that follow the ISO 216 standard. The most commonly used envelope sizes are from the C series. An A4 piece of paper will fit into a C4 envelope. The DL envelope has a different aspect ratio to the C series, which is why it does not appear in that series. The DL envelope is the most common envelope used in business. DL is short for ‘Dimension Lengthwise’, however it was previously known as DIN Lang in Germany where it originated in the 1920s. An A4 sheet of paper folded three times, parallel to its smaller sides, will fit into a DL envelope.
Format | Width × Height (mm) | Width × Height (in) |
---|---|---|
DL | 220 × 110 mm | 8.661 × 4.331 in |
C7 | 114 × 81 mm | 4.488 × 3.189 in |
C7/C6 | 162 × 81 mm | 6.378 × 3.189 in |
C6 | 162 × 114 mm | 6.378 × 4.488 in |
C6/C5 | 227 × 114 mm | 8.937 × 4.488 in |
C5 | 229 × 162 mm | 9.016 × 6.378 in |
C4 | 324 × 227 mm | 12.756 × 8.937 in |
C3 | 458 × 324 mm | 18.031 × 12.756 in |
B6 | 176 × 125 mm | 6.929 × 4.921 in |
B5 | 250 × 176 mm | 9.843 × 6.929 in |
B4 | 353 × 250 mm | 13.898 × 9.843 in |
E4 | 400 × 280 mm | 15.748 × 11.024 in |