What is A3 size in mm?

What are the dimensions of A3 size in mm? You can read it below. We have an overview in millimetres also in inches and centimetres.

Dimensions A3 size in mm


width 420 mm x length 297 mm

Especially designers, graphic designers and other creatives often need the A3 size in millimetres. For example, when they start designing stationery, menus, magazine calendars or other resources in A3 size in design programs, such as InDesign. Therefore it is good to know that the A3 size in millimetres is 420 x 297 mm. Where the length is 420 millimetres and the width is 297 millimetres.

Calculate the size in millimetres with our handy calculation tool

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A3 size in millimetres with bleed area

Would you like to have your print file printed at a printer? Then one of the delivery specifications is often to use a bleed area of 3 mm (all around) in your print file. This changes the ‘gross’ size, so it is important that you do not forget this.

A bleed area of 3 mm means an extra 6 mm around your A3 paper size. Both in length and width. With an A3 this means that your net size is 420 x 297 mm. And the gross size (including bleed area) is 426 x 303 mm. Then the printer cuts away the bleed area, so that the background of your A3 flyer, menu card or calendar runs neatly to the edge.

Size Millimeter
4A0 1682 x 2378
2A0 1189 x 1682
A0 841 x 1189
A1 594 x 841
A2 420 x 594
A3 297 x 420
A4 210 x 297
A5 148 x 210
A6 105 x 148
A7 74 x 105
A8 52 x 74
A9 37 x 52
A10 26 x 37