Historically book sizes related to paper sizes and how they folded the paper to form the book. There are page sizes that simply reflect fold sizes and then there are trimmed sizes where they trim a folded sheet. The simple folded sizes are always cheaper to produce because they don’t take that extra step of trimming.
Each POD printer company is set up to produce books of certain sizes. See our spreadsheet for a handy guide. A traditional offset printer has more flexibility in size, but the POD digital printers only give authors a set number of choices. The POD printers focus on the most common and popular sizes, but each one has its own unique set of offerings. For example TheBookPatch and Lulu offer pocket size, while 48HourBooks offers a big selection of landscape photo books. There are a lot of sizes to choose from even though it’s limited by the set ups.
The best thing to do is start by looking at books in your genre. Then you can decide how you want to fit in given the balance between setting readers’ expectations and attracting readers’ attention. You could go to the library or the bookstore and measure books. That gives you a great sense of how things will line up and how maybe uniformity is not a great thing. Or you could hop on Goodreads and look for attractive books. The dimensions for all physical books sold through Amazon are given on Amazon, but I don’t advise browsing Amazon for attractive books because it is going to try to divert you to Kindle products which have no size. But after you notice an attractive shape elsewhere, then definitely look at the Product Details on Amazon for size.
When you have picked a desired size, check our list of printers for who can provide it. Our list is organized by size (square inches, then shape).
