A3 Paper Size, Dimensions and Format (A series)

A3 in millimetres

297 x 420 mm




Aspect ratio 1:1.41
Area (A) 124,740 mm²
Perimeter (P) 1,434 mm
Diagonal (d) 514.40 mm


The A3 format measures 297 x 420 mm or inches. An A3 paper fromat has an aspect ratio of 1:1.41. The Area of the A3 paper size is 124,740 mm² or 193.05 in² with a perimeter of 1,434 mm or 56.40 in. An A3 format has a diagonal length of 514.40 mm or 20.23 in. The A3 size belongs to the A series. In the A series there are a total of 19 paper sizes.

Other A Paper Sizes

There are a total of 19 A Paper Sizes.