Book Sizes and Why They Matter
By Preflight Books

So you’ve just completed your manuscript, how exciting! The next step is sending your work off to have it published and printed, but wait – which of the available book sizes should you choose? Should you do a custom size? What in the world is going on? Do not fear for Preflight is here and more than happy to help you pick the perfect book size for your soon-to-be stellar work!

What is trim size and how do you pick one?

Book size is referred to as the trim size, as it describes the height and width of the pages that need to be cut for your book. There are several factors that come into play when deciding on the trim size of your book:

  1. Industry Standard: Often the biggest factor, your book’s trim size is determined by what is viewed as the norm within the genre it falls. You would not want your short romance novel to be the size of a school textbook, now would you?
  2. Aesthetic Implications: Thinking about how much a print-run will cost is always on a self-publishing author’s mind. That is why it’s important to know what size will work best with your book. Trim size does not only focus on the height and width of your book, but the page number as well. Should you want there to be a certain amount of pages, it would be within your best interest to pick a size that accommodates your text.
  3. Always remember the reader: Knowing what a reader gravitates to will always help an author when picking a trim size. Keep your trim size of your novella similar to others that are available on the shelves. It is something your reader is familiar with and so they will unconsciously turn to your title since it is in a format they are experiencing.

Common Books Sizes and their Uses

A4 Portrait

A size often used for textbooks and comics, A4 standard book size is 297×210mm. This size is flexible because, when in landscape, it can be used for a children’s title. A4 is the go-to size for when you are an author interested in relaying a lot of information with graphic elements, or just illustrations.

A4 Landscape Book Size
A4 Portrait Book Size

A5 Standard

Novellas and fiction titles are often created in the A5 format, their size being 210mm ×148mm. These books are meant to make use of a maximum of 200 pages and are often small enough to pop into your bag. This makes them easy to transport but keeps them readable.

A5 Book Size

A3 Standard

The prime size of a coffee table book, an A3 book is 420 × 297mm. This size is used for books that make use of illustrations or photographs, giving the reader the ability to see all the fine details.

A3 Portrait Book Size
A3 Landscape Book Size

Royal Paperback

Royal paperback books have a measurement of 234×156mm. This book size is usually recommended for novels or non-fiction books over 150 pages. Due to the limited number of pages, this is actually the cheaper option for many self-publishing authors.

Royal Paperback Book Size

Trade Paperback

Trade paperback books are 129x198mm and are usually used for general fiction books. If you pick this size, your book will fit nicely on the shelves with other fiction books and be comfortable for the reader.

Trade Paperback Book Size

A4 Square

An A4 Square book is 210x210mm in size. This size is recommended for comic books, textbooks and coffee table books as well as for children’s books.

A6 Standard Size

The A6 Standard Size book is measured at 148x105mm and is good for pocket-sized books, devotionals and gift books. These sized books are easier to transport as they can be carried in the breast pocket of a shirt.

A6 size Book Size

A Graphic Overview of Book Sizes

Preflight Books Standard Book Sizes

Sizing up

Though it may seem menial, deciding on the perfect book size is important to best represent the content of your book. Here at Preflight, we pride ourselves in ensuring that your book matches your taste and will bring joy to your readers as much as the creation of it brought you. Get a quote to publish your book here or send an email to

Further Reading

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