Japanese poster are issued in these primary sizes:

B0 - measures 40" x 58" consisting of 2 'B1' sheets.

B1 - measures 29" x 40" . Most often this is a double size version of the B2 which would make it vertical, but sometimes it is presented horizontal with different artwork.

B2 - measures 20" x 29" and is the base size for most Japanese posters.

B3 - Nakazuri - (which means 'hanging inside') measures 14" x 20" about half the 'B2' used inside bus and train stations. Very similar to a mini sheet

B4 - measures 10" x 29" which is half the size vertically of the B2 poster and half BOTH ways of the STB. Sometimes called a Japanese insert or 'speed' poster.

B5 - Chirashi - a small promo poster similar to a herald or a flyer. Their measurements vary but the majority are about 7" x 10". These are quite often printed with information on the back.

STB - measures 20" x 58" which consists of 2 sheets of 'B2' posters over and under. These are sometimes called 'Tatekan' posters