Understanding trim sizes

If you’re getting a book ready for publication you will have definitely heard the term ‘Trim Size’, this comes from the process of printing and actually creating the book itself, your book being printed on large sheets of paper which are folded, bound and then trimmed to the appropriate size.

And this leads on to a very good (and often asked) question, what should the trim size of my book be?

Well, it depends, there are some rules as to what the industry expects certain genres and topics to be printed as, but in these days of self-publishing those rules aren’t followed as much as they once were.

Mass Market Books – 4” x 7”

These are books which were originally produced quite cheaply and sold in places like airports (their small size making them great for travel, you also see them in supermarkets too), the size is most commonly used for fiction. In self-publishing you’ll find that companies such as Ingram Spark print at this trim size but Amazon’s KDP do not print this small.

Trade Paperback – commonly 5”x8” to 6”x9”

The name Trade Paperback is a term used to indicate a book which is larger in size than that of the Mass Market book. Trade Paperbacks tend to be the most ‘common’ size and work well for both fiction and non-fiction. The main differential between fiction and non-fiction Trade Paperbacks being the paper color within the book itself, again, there is no set-in-stone rule, but you tend to find that most fiction is on cream paper and non-fiction upon white.

Workbooks & Manuals – 8.5”x11”

These are larger printed books and work well as they are the size of a standard letter sheet of paper, they give room for two columns of text with plenty of space for images and illustrations, they’re more likely to be printed in color and use white paper within (normally with a glossy finish).

Hardcovers – ranging from 5”x8” to 8.5”x11”

The smaller sizes tend to be more for fiction with the larger working better for non-fiction, workbooks and manuals, this goes for both Dust Jackets and Case Laminates.

Sizes currently on offer through KDP are:

5" x 8" (12.7 x 20.32 cm)
5.06" x 7.81" (12.85 x 19.84 cm)
5.5" x 8.5" (13.97 x 21.59 cm)
6" x 9" (15.24 x 22.86 cm)
6.14" x 9.21" (15.6 x 23.39 cm)
6.69" x 9.61" (16.99 x 24.41 cm)
7" x 10" x (17.78 x 25.4 cm)
7.44" x 9.69" (18.9 x 24.61 cm)
7.5" x 9.25" (19.05 x 23.5 cm)
8" x 10" (20.32 x 25.4 cm)
8.25" x 6" (20.96 x 15.24 cm)
8.25" x 8.25" (20.96 x 20.96 cm)
8.5" x 8.5" (21.59 x 21.59 cm)
8.5" x 11" (21.59 x 27.94 cm)
8.27" x 11.69" (21 x 29.7 cm)

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For IngramSpark the trim sizes on offer are:
For Paperback Books:
4 x 6" (154 x 102mm)
4 x 7" (178 x 102mm) 
4.25 x 7” (178 x 108mm)
4.37 x 7" (178 x 111mm) A
4.72 x 7.48" (190 x 120mm)
5 x 7" (178 x 127mm)
5 x 8" (203 x 127mm)
5.06 x 7.81" (198 x 129mm)
5.25 x 8" (203 x 133mm)
5.5 x 8.25" (210 x 140mm)
5.5 x 8.5" (216 x 140mm)
5.83 x 8.27" (210 x 148mm) A5
6 x 9" (229 x 152mm)
6.14 x 9.21" (234 x 156mm)
6.5 x 6.5" (165 x 165mm)
6.625 x 10.25" (260 x 168mm) (Graphic Novel)
6.69 x 9.61" (244 x 170mm) (Pinched Crown)
7 x 10" (254 x 178mm)
7.44 x 9.69" (246 x 189mm)
7.5 x 9.25" (235 x 191mm)
8 x 8" (203 x 203mm)
8 x 10" (254 x 203mm)
8 x 10.88" (276 x 203mm)
8.25 x 10.75" (273 x 210mm)
8.25 x 11" (279 x 210mm)
8.268 x 11.693" (297 x 210mm) A4
8.5 x 8.5" (216 x 216mm)
8.5 x 9" (229 x 216mm)
8.5 x 11" (280 x 216mm)
11 x 8.5" (216 x 280mm) Premium Color Only
​
And for Hardcovers:
5 x 8" (203 x 127mm) Case Lam/Cloth/Jacket
5.5 x 8.5" (216 x 140mm) Case Lam/Cloth/Jacket
5.83 x 8.27" (210 x 148mm) Case Lam
6 x 9" (229 x 152mm) Case Lam/Cloth/Jacket
6.14 x 9.21" (234 x 156mm) Case Lam/Cloth/Jacket
6.69 x 9.61" (244 x 170mm) Case Lam
7 x 10" (254 x 178mm) Case Lam
7.5 x 9.25" (235 x 191mm) Case Lam
8 x 8" (203 x 203mm) Case Lam
8 x 10" (254 x 203mm) Case Lam
8 x 10.88" (276 x 203mm) Case Lam
8.25 x 10.75" (273 x 210mm) Case Lam
8.5 x 8.5" (216 x 216mm) Case Lam
8.5 x 11" (280 X 216mm) Case Lam
11 x 8.5" (216 x 280mm) Case Lam, Premium Color Only

Again, there are no rules that you must stick to at all costs, the publishing world is constantly changing and standards that were fixed at one point are now more fluid than they have ever been.

​However, the goal of your chosen trim size is to ensure that the reader understands what the book is, and that it makes the reading of the book a more pleasurable experience, so choose wisely.