International Envelope Paper Sizes

Further Information

International standard ISO 269 defines several standard envelope sizes, which are designed for use with ISO 216 standard paper sizes.

The German standard DIN 678 defines a similar list of envelope formats.

Source: Wikipedia

Format Width x Height (mm) Width x Height (in)
DL 220 x 110 mm 8.7 x 4.3 in
C7 114 x 81 mm 4.5 x 3.2 in
C7/C6 162 x 81 mm 6.4 x 3.2 in
C6 162 x 114 mm 6.4 x 4.5 in
C6/C5 227 x 114 mm 8.9 x 4.5 in
C5 229 x 162 mm 9 x 6.4 in
C4 324 x 227 mm 12.8 x 8.9 in
C3 458 x 324 mm 18 x 12.8 in
B6 176 x 125 mm 6.9 x 4.9 in
B5 250 x 176 mm 9.8 x 6.9 in
B4 353 x 250 mm 13.9 x 9.8 in
E4 400 x 280 mm 15.7 x 11 in