The size of a specific book is measured from the head to tail of the spine, and from edge to edge across the covers.

However, in bookbinding, printing, and publishing, a series of terms are used to indicate the approximate size of a book. These terms are derived from the number of leaves created from a standard size sheet of paper (19" x 25") when each signature of the book is printed.

For example, a quarto book results when 4 leaves are created from each sheet of paper. The resulting book will be approximately 12.5" inches tall and 9.5" inches wide, before trimming. Each leaf usually has a printed page or an intentionally blank page on each side, so a quarto signature usually represents 8 pages of the book.

Octavo and quarto are the most common book sizes, but many books are produced in larger (folio) and smaller sizes as well. These terms are often abbreviated, using 4to for quarto; 8vo for octavo; and so on.

The printed signatures are bound together to form an entire book. Before the covers are bound to the book, the block of text pages is usually trimmed along the three unbound edges to open the folds of the paper and to produce smooth edges for the book. As a result, the final size of a book will depend on whether and how much the paper is trimmed; and the way the book is bound, particularly the covers used.

Also see bookbinding.

External links

• Book sizes from Bookbinding and the Conservation of Books.

• ABEbooks Glossary discusses modern usage

• Book Sizes from Books and Book Collecting

Books | Book design