ISO C series (envelopes)
C7/C6 envelope size
C7/C6 envelope measures 81 x 162 mm (3.19 x 6.38 in). Part of the ISO C series (envelopes).
Dimensions in every unit
| Unit | Width x height |
|---|---|
| Millimetres | 81 x 162 mm |
| Centimetres | 8.1 x 16.2 cm |
| Inches (decimal) | 3.189 x 6.378 in |
| Inches (fraction) | 3 3/16 x 6 3/8 in |
| Points (1/72 in) | 229.6 x 459.2 pt |
| Picas | 19.13 x 38.27 pc |
Pixel dimensions by resolution
| Resolution | Pixels | Megapixels |
|---|---|---|
| 72 dpi | 230 x 459 px | 0.1 MP |
| 96 dpi | 306 x 612 px | 0.2 MP |
| 150 dpi | 478 x 957 px | 0.5 MP |
| 200 dpi | 638 x 1,276 px | 0.8 MP |
| 300 dpi | 957 x 1,913 px | 1.8 MP |
| 600 dpi | 1,913 x 3,827 px | 7.3 MP |
300 dpi is the usual target for printed photos and artwork; 72–96 dpi is screen resolution.
Document size with bleed
| Bleed | Millimetres | Inches |
|---|---|---|
| 3 mm bleed (each side) | 87 x 168 mm | 3.425 x 6.614 in |
| 0.125 in bleed (each side) | 87.4 x 168.4 mm | 3.439 x 6.628 in |
How many C7/C6 envelope fit on a press sheet
| Sheet | Without bleed | With 3 mm bleed |
|---|---|---|
| A4 | 3-up | 3-up |
| A3 | 6-up | 6-up |
| SRA3 | 6-up | 6-up |
| Letter | 3-up | 3-up |
| Tabloid 11 x 17 in | 6-up | 6-up |
| 12 x 18 in | 6-up | 6-up |
| 13 x 19 in (Super B) | 10-up | 6-up |
| B2 (offset) | 24-up | 20-up |
| B1 (offset) | 48-up | 44-up |
Simple grid imposition with no gutters or gripper margin; real layouts may fit fewer.
The √2 system
C7/C6 envelope has an aspect ratio of 1 : 2 — close to √2 (1.4142). Folding or cutting it in half across the long side produces the next smaller size in the series with the same proportions, and two sheets side by side form the next larger size. This is why scaling between sizes in the series (for example on a photocopier) never crops or distorts the page.
This size is listed in the Wikipedia article on paper sizes under “International envelope and insert sizes”. Historic and regional sizes can vary between sources and mills.
Similar sizes
Frequently asked questions
What are the dimensions of C7/C6 envelope?
How many pixels is C7/C6 envelope at 300 DPI?
Sources & data
- Listed in the Wikipedia article “Paper size” (CC BY-SA 4.0).