ISO C series (envelopes)

C5 envelope size

C5 envelope measures 162 x 229 mm (6.38 x 9.02 in). Envelope for A4 folded once, or A5 unfolded.

162 x 229millimetres

6.38 x 9.02inches

1,913 x 2,705pixels @ 300 dpi

Dimensions in every unit

Unit	Width x height
Millimetres	162 x 229 mm
Centimetres	16.2 x 22.9 cm
Inches (decimal)	6.378 x 9.016 in
Inches (fraction)	6 3/8 x 9 in
Points (1/72 in)	459.2 x 649.1 pt
Picas	38.27 x 54.09 pc

Pixel dimensions by resolution

Resolution	Pixels	Megapixels
72 dpi	459 x 649 px	0.3 MP
96 dpi	612 x 866 px	0.5 MP
150 dpi	957 x 1,352 px	1.3 MP
200 dpi	1,276 x 1,803 px	2.3 MP
300 dpi	1,913 x 2,705 px	5.2 MP
600 dpi	3,827 x 5,409 px	20.7 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)	168 x 235 mm	6.614 x 9.252 in
0.125 in bleed (each side)	168.4 x 235.4 mm	6.628 x 9.266 in

How many C5 envelope fit on a press sheet

Sheet	Without bleed	With 3 mm bleed
A4	1-up	1-up
A3	2-up	2-up
SRA3	2-up	2-up
Letter	1-up	1-up
Tabloid 11 x 17 in	2-up	2-up
12 x 18 in	2-up	2-up
13 x 19 in (Super B)	4-up	2-up
B2 (offset)	9-up	8-up
B1 (offset)	18-up	16-up

Simple grid imposition with no gutters or gripper margin; real layouts may fit fewer.

The √2 system

C5 envelope has an aspect ratio of 1 : 1.4136 — 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.

Frequently asked questions

What are the dimensions of C5 envelope?

C5 envelope is 162 x 229 mm, which is 6.38 x 9.02 in (6 3/8 x 9 in).

How many pixels is C5 envelope at 300 DPI?

1,913 x 2,705 pixels at 300 dpi, or 957 x 1,352 at 150 dpi.

Sources & data

Dimensions per the relevant standard; see sources.