C4 paper size
C4 is part of the ISO C range (ISO 216). Commonly used for envelope for unfolded A4.
C4 dimensions
229 × 324 mm
9.016 × 12.756 inches · 22.9 × 32.4 cm ·
aspect ratio 1:1.415
All units
| Unit | Width | Height |
|---|---|---|
| Millimetres | 229 | 324 |
| Centimetres | 22.9 | 32.4 |
| Inches | 9.016 | 12.756 |
| Points (PostScript) | 649.1 | 918.4 |
Pixel dimensions by resolution
Pixels are not a property of the paper — they depend on the resolution you print at. Build the document at the size you will actually output.
| Resolution | Pixels (W × H) | Use for |
|---|---|---|
| 72 DPI | 649 × 918 | Screen and web only |
| 96 DPI | 866 × 1,225 | Windows screen default |
| 150 DPI | 1,352 × 1,913 | Draft and home printing |
| 300 DPI | 2,705 × 3,827 | Standard for commercial print and print-on-demand |
| 600 DPI | 5,409 × 7,654 | Fine art and high-detail line work |
300 DPI is the number you want in almost every case. Print-on-demand services, Etsy printables and commercial printers all expect it. Exporting at 72 DPI and enlarging does not add detail — it just prints the same pixels bigger and softer.
Other ISO C sizes
| Size | mm | inches | px at 300 DPI |
|---|---|---|---|
| C5 | 162 × 229 | 6.38 × 9.02 | 1,913 × 2,705 |
| C6 | 114 × 162 | 4.49 × 6.38 | 1,346 × 1,913 |
| DL | 110 × 220 | 4.33 × 8.66 | 1,299 × 2,598 |
Common questions
What size is C4 in millimetres?
C4 is 229 × 324 mm.
What size is C4 in inches?
9.016 × 12.756 inches, which is 22.9 × 32.4 cm.
How many pixels is C4 at 300 DPI?
2,705 × 3,827 pixels. That is the canvas size to use for anything going to a commercial printer. For screen-only use, 72 DPI gives 649 × 918 px.
What is C4 used for?
Envelope for unfolded A4.