Standard Book Sizes: A Guide to Choosing the Right Dimensions

Choosing the Perfect Book Size: Your Comprehensive Guide

Books come in a myriad of sizes, each tailored for different reading experiences and publishing standards. From the pocket-sized volumes that offer portability to the large coffee table publications that boast high-quality imagery, size significantly influences a book’s purpose and appeal. In the publishing industry, these sizes are not random but are categorised into standard dimensions, which facilitate production, distribution, and shelving.

Standard book sizes have evolved through history, shaped by technological advancements and consumer preferences. They are referred to with terms such as ‘A4’, ‘trade paperback’, and ‘mass-market paperback’, which denote specific measurements and uses. Understanding these standards is crucial for authors, book publishers, and designers as it impacts design choices, printing costs, and the marketability of a book.

These dimensions often vary between countries following different publishing conventions. In the UK, for example, the most commonly used book sizes include A-format, B-format, and Royal, with each size serving distinct markets and genres. These standards help establish consistency within the industry and create a more organised and efficient way to reach readers.

Standard Book Formats

In publishing, books are commonly formatted into specific sizes to meet different market demands and usage scenarios. The following subsections describe the most common standard book formats.

Mass Market Paperbacks

Mass market paperbacks are affordable, compact editions commonly found in newsagents and supermarkets. They usually measure around 110mm x 178mm. These books are designed for a wide readership and are suitable for a variety of genres, including romance, mystery, and fantasy.

  • Common sizes (W x H):
    • A-format: 110mm x 178mm
    • B-format: 130mm x 198mm

Trade Paperbacks

Trade paperbacks are larger than mass market editions and are often used for literary works and novels. They typically measure 135mm x 216mm, providing a balance between portability and readability. This format is favoured for bookshop displays due to its premium aesthetic.

  • Common sizes (W x H):
    • Royal: 156mm x 234mm
    • Demy: 138mm x 216mm

Hardcover Books

Hardcover books offer durability with their rigid protective covers, often accompanied by a dust jacket. They are preferred for high-quality prints and are treasured by collectors. Standard sizes include 138mm x 216mm and 187mm x 246mm, alongside more bespoke options.

  • Common sizes (W x H):
    • Royal: 156mm x 234mm
    • Demy: 138mm x 216mm
    • Medium: 165mm x 242mm

Dimensions by Genre

Book dimensions vary significantly across different literary genres, catering to different reading experiences and audience needs. This section offers specifics on standard sizes for fiction, non-fiction, textbooks, and children’s books.


Fiction books typically come in several standard sizes. The most common sizes include:

  • A-format (110mm x 178mm): Often used for mass-market paperbacks.
  • B-format (130mm x 198mm): Popular for trade paperbacks.
  • C-format (135mm x 216mm): Preferred for large paperbacks.


Non-fiction titles, which can include a wide range of books from biographies to cookbooks, usually offer the following sizes:

  • Royal (156mm x 234mm): Common for paperbacks and hardbacks requiring more space for text or images.
  • Demy (138mm x 216mm): A frequent choice for trade books.


The standard dimensions for textbooks reflect their need for space to display content clearly:

  • A4 (210mm x 297mm): Standard for textbooks requiring large illustrations or complex layouts.
  • B5 (176mm x 250mm): Used when portability is also a consideration.

Children’s Books

Children’s books are designed to be engaging and often deviate from standard sizes to accommodate rich illustrations and interactive elements. Common sizes include:

  • Square (210mm x 210mm): Used for picture books.
  • Quarto (248mm x 305mm): Ideal for larger picture books with detailed illustrations.

Each genre’s standard book size is thoughtfully chosen to enhance the reader’s experience, considering factors such as readability, portability, and the nature of the content.

International Standard Book Sizes

International standard book sizes are primarily determined by the ISO 216 standard, which defines the A series of paper sizes. The United States, however, uses its own system for standard book sizes.

ISO A Sizes

The ISO A series of paper sizes is based on a constant width to height ratio of 1:√2. This allows for each size to be proportionally the same when scaled up or down. A4 (210 x 297 mm) is the standard size for most books worldwide, but sizes can range substantially from A0 (841 x 1189 mm), the largest, down to A10 (26 x 37 mm), the smallest.

Here is a list of common ISO A sizes used for books:

  • A4: 210 x 297 mm
  • A5: 148 x 210 mm
  • A6: 105 x 148 mm

US Book Sizes

Books published in the United States often differ in size from the ISO standard and are typically categorised into various names and dimensions. Trade size refers to the most common size for general interest books, measuring approximately 6 x 9 inches (152 x 229 mm). Other common sizes in the US include Mass Market Paperback, which measures around 4.25 x 6.87 inches (108 x 175 mm), and Textbook, which can vary but commonly measured at 7 x 10 inches (178 x 254 mm).

The following table shows examples of US book sizes:

Name Dimensions (inches) Dimensions (mm)
Mass Market Paperback 4.25 x 6.87 approx. 108 x 175
Trade 6 x 9 approx. 152 x 229
Textbook 7 x 10 approx. 178 x 254


In conclusion, it is critical for writers, publishers, and designers to comprehend the wide range of typical book sizes. These sizes meet different reader preferences, genres, and market demands; they range from small mass market paperbacks to bigger coffee table editions. These standardised proportions, which have their roots in historical evolution and technological advancements, make production, distribution, and shelving within the publishing sector more efficient.

Every standard has a function and helps make books more organised and accessible globally. Examples of these standards are the UK’s A-format and B-format, the international ISO A sizes, and the unique dimensions used in the US. For all intents and purposes, including portability, readability, and displaying detailed illustrations, the careful choice of book sizes is essential to improving the reading experience and guaranteeing the smooth distribution of literary works among a wide range of consumers.

Leave a Reply

Your email address will not be published. Required fields are marked *


Signup for our newsletter to get updated information, promotion & Insight

Get a Quote