A3 paper size

All paper sizes
ISO A Seriesportrait · 1:1.414 (√2)

Format profile / A3

A3

297 × 420 mm · 11.69 × 16.54 in

Width

297 mm

Height

420 mm

Area

1,247 cm²

A3297 × 420 mm

Finished-size ledger

Millimeters297 × 420 mm
Centimeters29.7 × 42 cm
Inches11.69 × 16.54 in
Proportion1:1.414 (√2)
Orientationportrait
StandardISO A Series

Pixel canvas by resolution

rounded to whole pixels
72 DPI842 × 1,191 px
96 DPI1,122 × 1,588 px
150 DPI1,754 × 2,481 px
300 DPI3,507 × 4,962 px
600 DPI7,014 × 9,924 px

Bleed and safe-area canvases

confirm with your printer

3 mm on every edge

303 × 426 mm

Artwork canvas with bleed. Keep essential content inside roughly 291 × 414 mm if the same distance is also used as a simple safety margin.

5 mm on every edge

307 × 430 mm

Artwork canvas with bleed. Keep essential content inside roughly 287 × 410 mm if the same distance is also used as a simple safety margin.

Closest standard formats

both edges compared

Where A3 fits

4 common uses
01Small posters
02Large presentations
03Spreadsheets
04Menus

Next in the ISO A drawer

larger / smaller

Set up A3 artwork without guessing

Start the document at the finished size—297 × 420 mm—and add the bleed your printer specifies outside that edge. A common 3 mm bleed produces a 303 × 426 mm artwork canvas. Keep type, logos, folds, and other critical details inside the trim line; a safety margin is not the same thing as bleed.

Pixel dimensions only become meaningful when paired with a resolution. At 300 DPI, this format is 3,507 × 4,962 pixels. Changing that number in an export dialog without resampling does not add image detail—it only changes the declared physical scale.

A3 belongs to ISO A Series. Its proportion is 1:1.414 (√2); the √2 family is designed so a half-sheet keeps the same shape, which makes layouts easier to scale between related formats.

StandardISO A
Orientationportrait
Area1,247 cm²
At 300 DPI3507 × 4962