Amazon has a range of book sizes to choose from and these are shown in inches with cm in brackets.
So, when it comes to your book, does size matter?
Well, for a start off, the size of your book will determine how much it costs to publish it. You also need this information to format your manuscript so that it’s ready for publishing.
You can choose whatever size you want for your book, however, there are some industry standards that will make it easier for you to choose.
Amazon book sizes are based on US paper sizes, which are different to the ISO 216 standard paper sizes used in Europe (A1, A2, A3, A4, A5 etc.) and are shown in imperial inches rather than metric cm.
Most paperbacks books, also known as Trade Paperbacks are: 5.5 x 8.5 in (13.97 x 21.59 cm) or 6 x 9 in (15.24 x 22.86 cm). The smaller size is what I used for my journals, habit trackers and portable planners. The larger size is what I use for my notebooks. Both sizes are portable enough to fit into a ladies handbag.
Manuals, workbooks and planners by the very nature tend to be bigger. Mine have been 8 x 10 in (20.32 x 25.4 cm) but you can make your book slightly bigger with 8.5 x 11 in (21.59 x 27.94 cm) which is the US Letter size, and similar to A4 (21 cm x 29.7 cm).
This is a summary of the main book types and book sizes in inches, provided by Reedsy (see link below):
Fiction: 4.25 x 6.87 in, 5 x 8 in, 5.25 x 8 in, 5.5 x 8.5 in, 6 x 9 in
Novella: 5 x 8 in
Children’s: 7.5 x 7.5 in, 7 x 10 in, 10 x 8in
Textbooks: 6 x 9 in, 7 x 10 in, 8.5 x 11 in
Non-fiction: 5.5 x 8.5 in, 6 x 9 in, 7 x 10 in
Memoir: 5.25 x 8 in, 5.5 x 8.5 in
Photography: Whatever you see fit!
Please note: The sizes here are for your books trim-size with no bleed.
Book size is quite a big topic, but hopefully, this post will help you get started.
For further information, check out these posts:
What Are the Standard Book Sizes in Publishing? by Reedsy
Self-Publishing Basics: How to Pick the Size of your Book by The Book Designer