C7 paper size
81 × 114 mm
3.19 × 4.49 inches · 8.1 × 11.4 cm · aspect ratio 1:1.41
What C7 is for
C7 is 81 × 114 mm, sized to hold an A7 sheet unfolded, and is the small card envelope used for gift tags and compliment slips. It is below the minimum size some postal services will handle on its own, so it is usually enclosed rather than posted.
C7 in every unit
| Unit | Width | Height |
|---|---|---|
| Millimetres | 81 mm | 114 mm |
| Centimetres | 8.1 cm | 11.4 cm |
| Inches | 3.19 in | 4.49 in |
| Points (PostScript) | 230 pt | 323 pt |
C7 in pixels
Pixel dimensions depend entirely on the resolution you are working at — there is no single "pixel size" for a sheet of paper.
| Resolution | Pixels | Use |
|---|---|---|
| 72 DPI | 230 × 323 | Screen preview only — far too coarse to print |
| 150 DPI | 478 × 673 | Draft printing, internal documents |
| 300 DPI | 957 × 1346 | The standard for commercial print |
| 600 DPI | 1913 × 2693 | Fine detail, line art, archival scanning |
Setting up a print document? Use 300 DPI and add 3 mm of bleed on every edge unless your printer specifies otherwise.
How C7 relates to the rest of the series
C7 is C0 halved 7 times. Halving a sheet across its longer side is what generates the next size down, and because the sides are in a 1:√2 ratio the proportions survive every fold — which is the entire reason the series exists.
That makes 128 sheets of C7 exactly one sheet of C0, with nothing left over. The area works out at 0.007813 m², since C0 is defined as one square metre.
Scaling to the next size up or down is a factor of √2 ≈ 1.414 on each edge, so enlarging C7 to the next size is 141% on a photocopier and reducing it is 71%. Those two numbers are on the preset buttons of most copiers for exactly this reason, and they are the same for every size in the series.
About C7
Takes an A7 sheet unfolded — the size of a small card envelope.
Other ISO C series sizes
| Size | Millimetres | Inches |
|---|---|---|
| C4 | 229 × 324 mm | 9.02 × 12.76 in |
| C5 | 162 × 229 mm | 6.38 × 9.02 in |
| C6 | 114 × 162 mm | 4.49 × 6.38 in |
| DL | 110 × 220 mm | 4.33 × 8.66 in |
| C3 | 324 × 458 mm | 12.76 × 18.03 in |
| Envelope No. 10 | 104.775 × 241.3 mm | 4.13 × 9.5 in |
| A7 Envelope (US) | 133.35 × 184.15 mm | 5.25 × 7.25 in |
Frequently asked questions
What size is C7 in mm?
81 × 114 mm.
What size is C7 in inches?
3.19 × 4.49 inches.
What size is C7 in pixels?
There is no single answer — it depends on resolution. At the print standard of 300 DPI it is 957 × 1346 pixels; at 72 DPI it is only 230 × 323.