Paper - The Graphic Design: Reference and Specification - page 63

In addition to the preceding A sizes, there are two series from which A sizes can be cut.
The series prefixed R and SR are designated as parent sheets for A sizes with tolerances
for accommodating bleeds and extra trims.

ISO R and SR Sheet Sizes and Inch Equivalents

ISO Size Size (millimeters) Size (inches) approx.

RA0 860 × 1220 33 7 ⁄ 8 × 48 1 ⁄ 8

RA1 610 × 860 24 1 ⁄ 8 × 33 7 ⁄ 8

RA2 430 × 610 17 × 24

SRA0 900 × 128 35 1 ⁄ 2 × 50 3 ⁄ 8

SRA1 640 × 900 25 1 ⁄ 4 × 35 1 ⁄ 2

SRA2 450 × 640 17 7 ⁄ 8 × 25 1 ⁄ 4

B0
1000 × 1414 mm 39 3 ⁄ 8 " × 55 5 ⁄ 8 "

B1
707 × 1000 mm 27 5 ⁄ 8 " × 39 3 ⁄ 8 "

B2
500 × 707 mm 19 5 ⁄ 8 " × 27 7 ⁄ 8 "
B3
353 × 500 mm 12 7 ⁄ 8 " × 19 5 ⁄ 8 "
B0
250 × 353 mm
9 7 ⁄ 8 " × 12 7 ⁄ 8 "

The B series is about half way between two A sizes and is intended as an alternative to the A sheets. ISO B series sheets are narrower
than the A series and are usually used for posters and wall charts. The B series is based on a B0 size of 1000 × 1414 mm.

ISO B Sheet Sizes and Inch Equivalents

ISO Size Size (millimeters) Size (inches) approx.

B0 1000 × 1414 39 3 ⁄ 8 × 55 5 ⁄ 8

B1 707 × 1000 27 7 ⁄ 8 × 39 3 ⁄ 8

B2 500 × 707 19 5 ⁄ 8 × 27 7 ⁄ 8

B3 353 × 500 12 7 ⁄ 8 × 19 5 ⁄ 8

B4 250 × 353 9 7 ⁄ 8 × 12 7 ⁄ 8

B5 176 × 250 7 × 9 7 ⁄ 8

B6 125 × 176 5 × 7

B7 88 × 125 3 1 ⁄ 2 × 5

B8 62 × 88 2 1 ⁄ 2 × 3 1 ⁄ 2