Understanding Cover Submission Requirements
In a nutshell, the dimensions for your book cover are:
Height = bleed + Trim Size Height + bleed
Width = bleed + Trim Size Width + Spine width + Trim Size Width + bleed
What is bleed exactly?
All you need to know is that bleed equals to 0.125" and it's the extra amount you have to extend your cover background, beyond the trim size.
How's the Spine width calculated?
The Spine width depends on the page count and the the color of the paper:
For White paper: multiply page count by 0.002252
For Cream paper: multiply page count by 0.0025
For Color paper: multiply page count by 0.002347
When it comes to the cover content, they're very picky
Here's the thing, no "live element" (non background images or text) closer than 0.25" to the edge (bleed lines). So make sure that anything that's not a background image is at least that far from the edge, they call that space the "live area" or "save zone."
To write on the spine or not to write on the spine, that is the question
Here's the catch, it turns out that CreateSpace cannot print anything on the spine, unless the book has at least 101 pages; when uploading a PDF that is.
In case your book does have more than 101 pages, then they would require that the text on the spine is at least 0.0625" away from the spine edges. Picky, I told you.
For example, if your spine is 1" wide, then the text shouldn't be wider than 0.875".
Here's an example fleshed out:
Let's say your book is a 6" x 9" with a 100 black and white pages, so:
Spine width = 100 * 0.002252 = 0.2252"
Height = 0.125" + 9" + 0.125" = 9.25"
Width = 0.125" + 6" + 0.2252" + 6" + 0.125" = 12.4752"
And thus your cover measurements are: 12.4752" X 9.25"
Just remember that all text and non-background images need to be 0.25" away from the edges.
a final thought,
Just be aware that CreateSpace is very picky and prone to reject a book cover which elements are barely within their specifications. Formatting a cover to their requirements does require the use of software like Adobe InDesign or Adobe Photoshop, let alone the knowledge and skill to effectively use them.
If you decide to go fully DIY and learn such skills, that's great! I am pretty sure they'll prove useful, just be mindful of the time and effort you're willing to spend on any given thing tangentially related to your main project. If, on the other hand, you hire an illustrator to design your cover from the bottom up and money is not an issue, that's great too! I am pretty sure you'll get value for each penny spent.
However, if you're on a budget and all you need is something to be tweaked a little, or you already have an idea for your cover but CreateSpace is giving you a hard time, check our affordable formatting services.