Envelope Dimensions made easy!

Envelope sizes can be a tricky thing to get your head around; it’s certainly a visual thing that a simple discussion just can’t explain. So we’ve done our best to lay it all out for you as simply as possible. We’ve taken a closer look into the C paper sizes as, being the most popular envelopes; we’ve had plenty of queries. Many have asked about the C4 envelope dimensions and C5 envelope dimensions are another frequent query. Take a look at the dimensions of the C series envelope sizes, (defined by ISO 216) given in the table below in both millimetres and inches.


Size               Height x Width (mm)                   Height x Width (in)
C0                 1297 x 917 mm                            51.5 x 36.1 in
C1                 1297 x 917 mm                             6.1 x x25.5 in
C2                  648 x 458 mm                              25.5 x 18.0 in
C3                  458 x 324 mm                              18.0 x 12.8 in
C4                  324 x 229 mm                              12.8 x 9.0 in
C5                  229 x 162 mm                              9.0 x 6.4 in
C6                  162 x 114mm                                6.4 x 4.5 in
C7                  114 x 81 mm                                 4.5 x 3.2 in
C8                  81 x 57 mm                                   3.2 x 2.2 in
C9                  57 x 40 mm                                   2.2 x 1.6 in
C10                40 x 28 mm                                   1.6 x 1.1 in




It comes in very useful to know that C envelope sizes are defined in the same was as A and B paper sizes with the same number. For example, C4 dimensions are the geometric mean of A4 and B4. Based on this, an envelope of the size between the two is produced which will neatly hold the A series paper of the same size —C4 Envelope = A4 sheet of paper unfolded.