Your KDP book size decides more than how big the book feels in the hand. Amazon KDP trim size is your printed book's width and height. Your cover file is bigger than the book itself, because it includes the spine and adds bleed. Trim size affects the page count you can print, your printing cost (which depends on whether the size counts as large), and the exact dimensions of your cover file.
Trim size is the starting point for every KDP cover template. If you fail to set the KDP book size at the beginning of your workflow, you may have to reformat the manuscript and rebuild your cover later.
KDP Always lists all Amazon KDP trim sizes below, shows you the genre each trim size suits, and explains how to choose. Want your cover dimensions once you pick a size? KDP Always's free KDP cover calculator turns a trim size and page count into exact numbers for you.
Which KDP trim sizes can you choose from?
Amazon KDP offers 16 paperback trim sizes and 5 hardcover trim sizes. KDP Always has sorted all KDP trim sizes for you, listed as width by height, along with the genre each is typically used for.
| Trim size | Regular or large | Paperback | Hardcover | Typical genre |
|---|---|---|---|---|
| 5" x 8" | Regular | Yes | No | Inspirational books, middle-grade fiction |
| 5.06" x 7.81" | Regular | Yes | No | Varies |
| 5.25" x 8" | Regular | Yes | No | Thrillers, mysteries, self-help, memoir |
| 5.5" x 8.5" | Regular | Yes | Yes | General nonfiction, YA fantasy and sci-fi |
| 6" x 9" | Regular | Yes | Yes | General fiction, reference |
| 6.14" x 9.21" | Large | Yes | Yes | Varies |
| 6.69" x 9.61" | Large | Yes | No | Varies |
| 7" x 10" | Large | Yes | Yes | Reference |
| 7.44" x 9.69" | Large | Yes | No | Varies |
| 7.5" x 9.25" | Large | Yes | No | Varies |
| 8" x 10" | Large | Yes | No | Varies |
| 8.25" x 6" | Large | Yes | No | Varies |
| 8.25" x 8.25" | Large | Yes | No | Varies |
| 8.25" x 11" | Large | No | Yes | Varies |
| 8.27" x 11.69" (A4) | Large | Yes | No | Varies |
| 8.5" x 8.5" | Large | Yes | No | Children's picture books |
| 8.5" x 11" | Large | Yes | No | Workbooks, textbooks |
Want something different? Paperbacks can also use a custom trim size, as long as the width and height stay inside the range KDP sets, which Amazon KDP explains on its Print Options page. However, hardcovers only come in the five sizes above.
What is the most common Amazon KDP book size?
6" x 9" is the most common KDP trim size for books in the US, and it is the default when you set up a new book. If you have no strong reason to pick something else, it is a safe Amazon KDP book size.
The next question to pay attention to is whether a size counts as regular or large. Amazon KDP calls a book a large trim size when it is wider than 6.12" or taller than 9", and the difference shows up in your printing cost.
If you also want a hardcover edition, 6" x 9" and 5.5" x 8.5" are the two regular trim sizes that come in both paperback and hardcover. Not sure 6" x 9" fits your kind of book? How to choose a KDP book size for your genre helps you decide.
How do KDP print sizes affect page count and printing cost?
First of all, your trim size limits how many pages you can print. Amazon publishes a minimum and maximum page count for each KDP trim size, and the limits depend on ink and paper type too. KDP Always has noticed three patterns that are worth knowing:
- Most paperback KDP print sizes allow up to 828 pages with black ink on white paper, but a few sizes, such as 8.5" x 11", top out far lower.
- Standard color is not available for A4 or for hardcover.
- Hardcovers run from 75 to 550 pages.
See below how the limits work for each ink and paper option:
| Trim size | Black ink, white paper | Black ink, cream paper | Black ink, groundwood paper | Standard color | Premium color |
|---|---|---|---|---|---|
| Paperback: 5" x 8" up to 8" x 10" (11 sizes) | 24 to 828 | 24 to 776 | 24 to 812 | 72 to 600 | 24 to 828 |
| Paperback: 8.25" x 6" and 8.25" x 8.25" | 24 to 800 | 24 to 750 | 24 to 784 | 72 to 600 | 24 to 800 |
| Paperback: 8.5" x 8.5" and 8.5" x 11" | 24 to 590 | 24 to 550 | 24 to 578 | 72 to 600 | 24 to 590 |
| Paperback: 8.27" x 11.69" (A4) | 24 to 780 | 24 to 730 | 24 to 764 | Not available | 24 to 590 |
| Hardcover: every size | 75 to 550 | 75 to 550 | Not available | Not available | 75 to 550 |
Secondly, printing cost also depends on trim size. Amazon KDP states that large trim sizes cost more to print than regular trim sizes, so moving from 6" x 9" to 8.5" x 11" can change your profit margin even if the page count stays the same. From KDP Always's experience, this is the part many authors omit. Want to check which sizes count as large? The Regular or large column in the trim size table shows each one.
How to choose a KDP book size for your genre
KDP Always has seen a lot of authors struggle with choosing the right KDP book size, and recommends starting with the size most books in your genre use. Those sizes are often regular sizes, which cost less to print, and readers already expect them. If you want your book to stand out, KDP Always suggests doing it with your cover and content rather than an unusual trim size.
- Look at your genre. Check the table above and find comparable bestsellers on Amazon. Match their size unless you have a reason not to.
- Check your page count. Make sure your estimated pages fit the limits for that size and your ink and paper choice.
- Check the price. If you are choosing between a regular and a large size, compare printing cost before you decide.
- Check the binding. If you want a hardcover too, only five sizes are available, so pick from those. You'll also need a separate KDP hardcover template for that edition.
- Check your content. Workbooks, textbooks, and picture books are typically printed at large sizes.
Here is another tip. If you are torn between two sizes, you can always order a proof copy of each. Holding both in hand may help you settle the decision faster than any chart.
How big should your Amazon KDP cover size be for your book size?
Your cover file is larger than your trim size. Cover width is the back cover, spine, and front cover added together, plus bleed on both sides, and cover height is your trim height plus bleed on the top and bottom. Although trim size fixes the height and the front and back widths, the spine depends on page count and paper type. For example, a 100-page and a 400-page paperback with the same trim size need different cover widths.
From working with tons of authors, KDP Always knows that the spine is the hard part, because each paper type has its own thickness. Change your page count once, even by a few pages, and the spine and every cover number move with it. Get one wrong, and the cover has to be rebuilt.
Overwhelming, we know. How about skipping the hand math and letting KDP Always do the work for you? Try KDP Always's free KDP cover calculator, meticulously built around 150+ Amazon KDP print rules. Simply enter your trim size, page count, and paper type, and you can instantly get your exact Amazon KDP cover size and a ready-to-use template.
Frequently asked questions
6" x 9" is the most common Amazon KDP book size in the US, and it is the default trim size when you set up a new book. 6" x 9" is also a regular trim size, so it avoids the higher printing cost of large trim sizes.
Amazon lists 16 paperback and 5 hardcover KDP trim sizes. Paperbacks can also use a custom trim size within a set width and height range, while hardcovers cannot.
Yes. Amazon charges more for large trim sizes. A trim size counts as large when it is wider than 6.12" or taller than 9". Page count, ink, and paper type also affect the price.
Yes. Your trim size sets the base height of your cover, and it is one of the numbers that sets the total width. Page count and paper type decide the spine, so two books with the same trim size can still end up with a different Amazon KDP cover size. A free KDP cover calculator from KDP Always will work out the exact numbers for you.
No. Amazon KDP locks the trim size once a paperback or hardcover is published, and the only way to change it is to create a new edition. Choose your Amazon KDP book size before you design anything. Download a free template with the KDP cover calculator from KDP Always to start with.