A3 Size In mm (Millimeter)

What is the exact A3 size in mm (millimeters)? Find out exact A3 paper size dimensions in mm for your printing or designing job.

A3 Paper Size in mm

A3 is an ISO standard paper size, and the actual dimensions are defined in mm. So the A3 size in mm that we give you below is actually the the very size defined in the ISO 216 paper size standard.

The size of one sheet of A3 paper in mm is 420mm x 297mm.

Notes To A3 Dimensions in mm

  • mm is an SI unit, the abbreviation of millimetre (international spelling) or millimeter (American spelling).
  • As A3 is an ISO standard paper size, therefore this A3 size in mm information gives you exact data.
  • To find out more information on the A3 paper size, click on the link.
    • A3 Paper Size in mm