C2 Envelope Size
C2 measures 458 × 648 mm (18.03 × 25.51 in). The C series is used for envelopes.
| Millimetres | 458 × 648 mm |
|---|---|
| Centimetres | 45.8 × 64.8 cm |
| Inches | 18.03 × 25.51 in |
| Aspect ratio (long ÷ short) | 1.415 |
| Series | ISO 269 C series (envelopes) |
| Fits | An A2 sheet laid flat fits inside a C2 envelope |
| Fits inside | A C2 envelope fits inside a B2 envelope |
Where you will see C2
C2 is a large envelope for sheets up to A2.
How C2 relates to A and B sizes
In the ISO 269 C series, each C size is slightly larger than the A size with the same number (420 × 594 mm for A2), so a flat A2 sheet fits inside a C2 envelope. The C2 envelope in turn fits inside a B2 envelope (500 × 707 mm).
Frequently asked questions
What size is a C2 envelope?
A C2 envelope is 458 × 648 mm (18.03 × 25.51 inches).
What fits in a C2 envelope?
A flat A2 sheet (420 × 594 mm) fits in a C2 envelope with a small margin of 38 mm in width and 54 mm in height.
Related
- C1 Envelope Size648 × 917 mm
- C3 Envelope Size324 × 458 mm
- A2 Paper Size420 × 594 mm
- B2 Paper Size500 × 707 mm
Last updated: 2026-10-03