A4 Size:  210 X 297mm/ 8.3 x 11.7”
 
A3 Size:  297 x 420mm/ 11.7 x 16.5”
 
A2 Size:  420 X 594mm/ 16.5 x 23.4”
 
A1 Size:  594 x 841mm/ 23.4 x 33.1”