Deciding on the Size of Your Book

The first and most important step in designing your book is deciding on its size. The dimensions of your book—commonly referred to as the "trim size"—must be established before moving on to layout, formatting, or any other design considerations. The trim size directly affects not only the visual appeal of your book but also its practicality, production costs, and overall readability.

When choosing a book size, the genre of your book plays a significant role in determining the most suitable option. Different genres have established conventions for book sizes, which are based on both reader preferences and production standards. Below is a guide to help you decide, with both imperial and metric sizes provided:

• Novels and Fiction:
  For fiction, particularly novels, a compact size is preferred for ease of handling. Common sizes include 5" x 8" (127mm x 203mm) or 5.5" x 8.5" (140mm x 216mm). These sizes are economical to print and are popular for their portability. Smaller book sizes are also ideal for books with fewer pages, as they prevent the book from feeling overly thin and help create a polished, substantial appearance.
• Nonfiction and Memoirs:
  Nonfiction books, such as memoirs or self-help books, are often slightly larger to allow for more content per page and easier readability. Sizes like 6" x 9" (152mm x 229mm) or 7" x 10" (178mm x 254mm) are common. These dimensions balance the professional appearance of the book with a comfortable reading experience.
• Children’s Books:
  Children’s books tend to have larger, more square dimensions to accommodate illustrations. Sizes like 8" x 8" (203mm x 203mm) or 8.5" x 11" (216mm x 279mm) work well for picture books, allowing images to shine while keeping text clear and easy to follow. For metric considerations, sizes such as 210mm x 210mm are also popular for square books.
• Photography and Art Books:
  Visual-heavy books such as photography collections or art books benefit from larger, landscape-oriented sizes. Popular dimensions include 11" x 8.5" (279mm x 216mm) or 12" x 12" (305mm x 305mm). Metric options include 297mm x 210mm (A4 landscape) or 300mm x 300mm for square designs, providing ample space for high-resolution images. However, landscape books can be more costly to produce. This is because digital press sheet size restrictions can increase printing complexity, particularly for saddle-stitched books. Similarly, covers for landscape books in perfect-bound or hardcover formats require additional considerations, often resulting in higher production costs.
• Academic and Reference Books:
  For textbooks, guides, or reference materials, functionality is key. A larger format like 8.5" x 11" (216mm x 279mm) or 210mm x 297mm (A4) allows for detailed diagrams, charts, and larger blocks of text, making these books easier to use for study or research.

Metric Overview of Common Book Sizes:

• Novels: 127mm x 203mm, 140mm x 216mm
• Nonfiction: 152mm x 229mm, 178mm x 254mm
• Children’s Books: 203mm x 203mm, 210mm x 210mm, 216mm x 279mm
• Art/Photography Books: 210mm x 297mm (A4), 300mm x 300mm
• Textbooks/Reference: 210mm x 297mm (A4), 216mm x 279mm

Setting Up Page Size and Margins in Microsoft Word

Once you've chosen the appropriate size for your book, you’ll need to set up the page dimensions in Microsoft Word to reflect this. Here’s how to do it, including mirror margins of 20mm and a gutter of 0:

• Open your document in Microsoft Word.
• Go to the Layout tab on the ribbon.
• Click on Size in the Page Setup group.
• Select a predefined size from the dropdown or choose More Paper Sizes to enter custom dimensions for your book (e.g., 152mm x 229mm for a 6" x 9" book).
• Next, click on Margins in the Page Setup group.
• Select Custom Margins at the bottom of the dropdown.
• In the Margins section of the Page Setup dialog box, set:
• Top, Bottom, Left, and Right margins to 20mm.
• Change Multiple pages to Mirror margins to ensure inner and outer margins adjust for binding.
• In the Gutter field, set the value to 0mm.
• Click OK to apply the settings.

Mirror margins will ensure that the inner margins are slightly wider than the outer ones when printed, accommodating the binding and making the content easier to read. For smaller page counts, the gutter can remain at zero, as there will be minimal curvature in the spine.