Standard reference size

A3 Paper

A3 paper — double the size of A4, good for posters.

Dimensions: 297 × 420 mm
Aspect ratio: 1:1.414
Orientation: portrait

1:1.414

Copy and use

Dimensions297 × 420

Ratio1:1.414

CSSaspect-ratio: 1 / 1.414;

Common uses

Posters
Presentations
Large documents

Source and status

Standard reference size

No fixed official platform requirement is claimed for this working size.