Printer Paper Size

International Envelope Paper Sizes Dimensions

C4 International Envelope

C4 Paper Size

Dimensions: 229 × 324 mm (9.02 × 12.76 in)

229 × 324mm

9.02 × 12.76 in

C4 is a widely used paper size for C4 envelopes are used for mailing full-page A4 documents, certificates, magazines, and business contracts that should not be folded. It's part of the International Envelope Paper Sizes standard.

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International Envelope Paper SizesInternational Envelope Paper SizesWidely used

229 mm

324 mm

What size is C4 paper?

An C4 piece of paper measures 229 × 324 mm or 9.02 × 12.76 inches. It is part of the International Envelope Paper Sizes standard.

Units	Width × Height
Metric millimeters (mm)	229 × 324 mm
Metric centimeters (cm)	22.90 × 32.40 cm
Metric meters (m)	0.229 × 0.324 m
Imperial inches (in)	9.02 × 12.76 in
Typographic points (1/72 inch) (pt)	649.13 × 918.43 pt
Typographic picas (1/6 inch) (pc)	54.09 × 76.54 pc
Pixels at 300 DPI (px)	2,705 × 3,827 px

C4 is part of the international envelope paper sizes standard. International envelope sizes follow the ISO 269 standard. The DL envelope is the most commonly used internationally, designed to hold an A4 sheet folded in thirds.

Also called: C4 Envelope, ISO C4 Envelope.

Quick facts

Size (mm)229 × 324 mm
Size (inches)9.02 × 12.76 in
Aspect ratio1 : 1.41
StandardInternational Envelope Paper Sizes
Common useC4 envelopes are used for mailing full-page A4 documents, certificates, magazines

Compare C4 with other sizes

Uses for C4

C4 envelopes are used for mailing full-page A4 documents, certificates, magazines, and business contracts that should not be folded.

International correspondence
Mailing documents without folding
Card and invitation mailings
Courier and records delivery

Printer tip

Load envelopes one at a time or in the dedicated envelope slot, set the flap side correctly, and choose the exact envelope size in the driver.

What fits in C4?

An envelope must be slightly larger than its contents. Check the internal dimensions, not only the nominal size, and leave room for the fold and flap when inserting documents.

C4 at common DPI

Pixel dimensions for C4 at popular resolutions. Rounded to whole pixels; physical sheet remains 229 × 324 mm.

96 DPI

866 × 1,225 px

Standard web & screen resolution

150 DPI

1,352 × 1,913 px

Medium quality draft printing

300 DPI

2,705 × 3,827 px

High quality commercial print

C4 at 72, 96, 150, 300 and 600 DPI
DPI	Width (px)	Height (px)
72	649	918
96	866	1,225
150	1,352	1,913
300	2,705	3,827
600	5,409	7,654

Last reviewed: 14 September 2026

Frequently Asked Questions

What are the dimensions of C4?

C4 measures 229 × 324 mm (9.02 × 12.76 inches).

How many pixels is C4 at 300 DPI?

C4 is 2705 × 3827 pixels at 300 DPI. Changing DPI changes pixel count, not its 229 × 324 mm physical dimensions.