The dimensions of the B series paper sizes, as defined by ISO 216, are given in the table below in both millimetres and inches. The B Series paper size chart to the right is a visual explanation of how the B paper sizes relate to each other.
Table of Paper Sizes From B0 to B10 
| Size | Height x Width (mm) | Height x Width (in) |
| B0 | 1414 x 1000 mm | 55.7 x 39.4 in |
| B1 | 1000 x 707 mm | 39.4 x 27.8 in |
| B2 | 707 x 500 mm | 27.8 x 19.7 in |
| B3 | 500 x 353 mm | 19.7 x 13.9 in |
| B4 | 353 x 250 mm | 13.9 x 9.8 in |
| B5 | 250 x 176 mm | 9.8 x 6.9 in |
| B6 | 176 x 125 mm | 6.9 x 4.9 in |
| B7 | 125 x 88 mm | 4.9 x. 3.5 in |
| B8 | 88 x 62 mm | 3.5 x 2.4 in |
| B9 | 62 x 44 mm | 2.4 x 1.7 in |
| B10 | 44 x 31 mm | 1.7 x 1.2 in |
B Series Paper Size Tolerances:
ISO 216 specifies tolerances for the production of B series paper sizes in the same way as for A series paper sizes, the specific details of which are as follows:
- ±1.5 mm (0.06 in) for dimensions up to 150 mm (5.9 in)
- ±2 mm (0.08 in) for lengths in the range 150 to 600 mm (5.9 to 23.6 in)
- ±3 mm (0.12 in) for any dimension above 600 mm (23.6 in)
B Series Paper Sizes Definition
The B series paper sizes are defined in ISO 216 in the following way.
The B series paper sizes were created in order to provide paper sizes that weren't covered by the A series, but also use an aspect ratio of 1:root2. B sizes are defined as size B(n) being the geometric mean of size A(n) and size A(n-1). The Geometric Means of 2 numbers being the square root of the product of the two numbers.
This system gives a useful property for enlarging and reducing documents in that the enlargement from A(n) to B(n) is the same as that from B(n) to A(n-1).
As with the A series paper the standard lengths and widths are rounded to the nearest millimetre.
