C3 at 150 dpi — 1913×2705 pixels

324×458 mm at 150 dpi comes to 1913×2705 pixels. On 80 g paper one sheet weighs 11.87 grams.

millimetres: 324 × 458 mm
inches: 12.76 × 18.03 in
Pixels: 1913 × 2705 px
All the pixels together: 5.17 MP
Uncompressed, that is: 14.8 MB
Area: 0.1484 m²
Ratio of the sides: 1 : 1.414
Sheets in one letter: 2

Weight per sheet

Paper weight is printed as g/m² — grams for one square metre. An A4 is a sixteenth of an A0, so 0.0625 m²; at 80 g that is 5 grams. If a letter must stay under 25 grams, 80 g paper gives you five sheets.

70 g/m²10.39 g
80 g/m²11.87 g
100 g/m²14.84 g
120 g/m²17.81 g
160 g/m²23.74 g
200 g/m²29.68 g
250 g/m²37.1 g
300 g/m²44.52 g

The envelope it fits

C2458×648mm

Nearby cells

Same size, other resolutions

How to read this

Dimensions are in millimetres. Leftover fractions are dropped when folding, exactly as the standard says.
Pixel counts are rounded. Printers usually ask for 300 dpi.
The weight is the paper alone. Add the envelope and the ink separately.
Letter and Legal are defined in inches, so folding them does not preserve the √2 ratio.

Frequently asked questions

Q. How big is C3?

324×458 mm, or 12.76×18.03 inches.

Q. How many pixels at 150 dpi?

1913×2705. That is 5.17 megapixels, or 14.8 MB uncompressed.

Q. What does one sheet weigh?

11.87 g on 80 g paper, 17.81 g on 120 g. A 25 g letter takes 2 of them.

Q. What envelope does it fit?

A C2 envelope, 458×648 mm.