# paper sizes in Japan

Japan has adopted the ISO series A sizes, but its series B sizes are slightly different.1 These sizes are sometimes called JIS B or JB sizes.

A JB0 sheet has an area of 1.5 square meters. The area of each size is the arithmetic average of the areas of the A series page with the same number and the A series page with the next higher number. So for example, the area of a JB4 page is the average of the area of an A4 sheet and an A5 sheet. (In the ISO B series, the area of each sheet is the geometric mean of the A sizes, that is, the square root of the sum of their areas.)

 JB0 1030 mm × 1456 mm JB1 728 mm × 1030 mm JB2 515 mm × 728 mm JB3 364 mm × 515 mm JB4 257 mm × 364 mm JB5 182 mm × 257 mm JB6 128 mm × 182 mm JB7 91 mm × 128 mm JB8 64 mm × 91 mm JB9 45 mm × 64 mm JB10 32 mm × 45 mm

1. JIS P 0138-61

### shiroku-ban

base size: 788 mm by 1091 mm (26 sun × 36 sun)

4 × 6/4 264 by 379 ( × 12.5 sun)

4 × 6/5 191 by 259 (printing on half sheets)

4 × 6/5 189 by 262

### kiku-ban

base size: 639 mm × 939 mm (21 sun × 31 sun)

Kiku 4, 227 mm × 306 mm

Kiku 5, 151 mm × 227 mm