A guide to the many envelope sizes that you may encounter in your daily business activities.

Type mm Suitable For

DL

110 × 220

1/3 A4

C7/C6

81 x 162

1/3 A5

C6

114 × 162

A6 (A4 folded twice)

C6/C5

114 × 229

1/3 A4

C5

162 × 229

A5 (A4 folded once)

C4

229 × 324

A4

C3

324 × 458

A3

C2

458 × 648

A2

C1

648 × 917

A1

C0

917 × 1297

A0

B6

125 × 176

C6

B5

176 × 250

C5

B4

250 × 353

C4

E3

280 × 400

B4