The following are sizes of the actual image. All prints have a white border - A1/A2 images have a 1" border all around, A3/A4 images have a 0.5" border.
A1 - 23.4 inches x 33.1 inches (59.5 cm x 84.1 cm)
A2 - 16.5 inches x 23.4 inches (42.0 cm x 59.4 cm)
A3 - 11.7 inches x 16.5 inches (29.6 cm x 41.9 cm)
A4 - 8.3 inches x 11.7 inches (21.0 cm x 29.7 cm)