what is b5 paper size

B5 paper size is part of the B series of paper sizes, which is defined by the ISO 216 international paper size standard. A B5 piece of paper measures 176 × 250 mm or 6.9 × 9.8 inches. It is slightly larger than A5 and smaller than A4. The B series was created to provide paper sizes that were not included in the A series, and it is commonly used in special situations such as posters, books, envelopes, and passports. B5 paper size offers more writing space than A5 but is easier to carry than a full-sized A4 notebook. It is a popular choice for notebooks and other stationery products.