Your interior is formatted, you have a cover image you love and a PDF that looks perfect. You upload it to KDP, wait for the previewer and the warning appears: text outside the safe area, spine doesn't match the page count, cover isn't the expected size. You fix it, upload again, and get a different error.
Almost nobody gets this wrong for lack of taste. They get it wrong because a print cover isn't a pretty picture with a title on top: it's a technical drawing whose measurements depend on three things many authors don't realize matter, the book's trim size, the paper type and the exact number of pages. Change one and the whole cover changes.
In this guide you'll find every measurement Amazon KDP asks for in 2026, how the spine is calculated, what bleed is and why it exists, a worked example with real numbers and a list of the mistakes that cause the most rejections. And at the end, how to make the cover without fighting the calculator.
Quick answer: Amazon KDP needs two different covers. The Kindle ebook cover is a JPG or TIFF image of 1,600 × 2,560 pixels (a 1.6:1 ratio), front only. The paperback cover is a single-page PDF with back cover, spine and front cover joined together, plus 0.125" (3.2 mm) of bleed on every outer edge. Its full width is: bleed + back cover + spine + front cover + bleed. The spine is the page count multiplied by the paper thickness: 0.002252" per page on white paper and 0.0025" on cream paper. For example, a 6" × 9" novel with 300 pages on cream paper needs a cover of 13" × 9.25". Spine text is only allowed from 80 pages up.
Two different covers: the ebook and the paperback
The first confusion is thinking there's one cover. On KDP you upload two files that look nothing alike, even if they share the artwork:
| Kindle ebook | Paperback | |
|---|---|---|
| What it includes | Front only | Back + spine + front in one piece |
| Format | JPG or TIFF | |
| Size | 1,600 × 2,560 pixels (recommended) | Depends on trim size, paper and pages |
| Bleed | None | 0.125" (3.2 mm) on every outer edge |
| Resolution | Whatever the pixel size gives | 300 DPI minimum |
| Color | RGB | Printed in CMYK even if you upload RGB |
The ebook cover is the easy one: a portrait image that doesn't change whether your book has 120 pages or 600. The paperback cover is the one that causes trouble, because it's a physical object that wraps around the block of pages and gets trimmed by the printer.
The practical approach is to design both at once. The front panel of the paperback, without the bleed, almost always works as the base for the ebook, once you adjust the proportions.
The Kindle ebook cover: size and format
Amazon recommends 1,600 pixels wide by 2,560 pixels tall, a 1.6:1 ratio. That size looks best on every screen: the store, the Kindle app, e-ink readers and phones.
The limits it accepts:
- Minimum: 625 × 1,000 pixels. Below that KDP rejects it; close to the minimum it looks blurry on large screens.
- Maximum: 10,000 pixels on the longest side and 50 MB.
- Format: JPG or TIFF, in RGB. If you export in CMYK the colors can look dull on screen.
One detail almost nobody mentions: if your cover has a white or very light background, it blends into Amazon's white page and looks like it's floating without edges. KDP recommends adding a thin gray border, three or four pixels wide, so the reader can see where it ends.
If your book will also have a print edition, don't give the ebook a different layout "because it looks better": a reader who sees both editions on the same product page needs to recognize them as the same book.
The paperback cover: how it's calculated
This is where all the trouble is, so let's go step by step. A paperback cover is one single wide image that, from left to right, contains:
bleed + back cover + spine + front cover + bleed
And from top to bottom: bleed + book height + bleed.
Notice the order: the back cover goes on the left and the front cover on the right. It seems obvious once you think about it (it's the book opened face down and laid flat), but it's a frequent mistake on someone's first cover.
Trim size
This is the final size of the book, the one you choose on KDP when you set up the print edition. For novels the most common is 6" × 9" (15.24 × 22.86 cm). Shorter fiction and mass-market style books often use 5" × 8" or 5.5" × 8.5", and in Europe many authors pick the A5-like 5.83" × 8.27".
Choose the trim size before formatting the interior. If you change it later, the page count, the spine and the whole cover change too.
Bleed: 0.125" on every side
Printers don't trim with micron precision. They print the cover on a larger sheet and then cut it, and that cut can drift slightly. If your background ended exactly on the trim line, any drift would leave a thin white sliver along the edge of the book.
That's why the background has to extend past the trim line: 0.125 inches, or 3.2 mm, on all four outer edges. That strip is called bleed and it's lost when the cover is trimmed. Don't put anything in it you want people to see.
Bleed only goes on the outer edges of the full piece. There's no bleed between the back cover and the spine or between the spine and the front cover.
The spine: it depends on pages and paper
Spine width is the only part of the cover you can't know in advance, because it depends on how many pages your interior has and how thick the paper is. KDP uses these thicknesses per page:
| Paper type | Thickness per page | Spine at 150 pages | Spine at 300 pages |
|---|---|---|---|
| White, black-and-white interior | 0.002252" (0.0572 mm) | 0.338" (8.6 mm) | 0.676" (17.2 mm) |
| Cream, black-and-white interior | 0.0025" (0.0635 mm) | 0.375" (9.5 mm) | 0.75" (19.1 mm) |
| White, standard color interior | 0.002252" (0.0572 mm) | 0.338" (8.6 mm) | 0.676" (17.2 mm) |
| White, premium color interior | 0.002347" (0.0596 mm) | 0.352" (8.9 mm) | 0.704" (17.9 mm) |
The formula is simple: page count × thickness per page. The hard part is the page count, which has to be the one in your final interior PDF, counting blank pages, the title page, the copyright page and the acknowledgments. Not the number you expect it to have, and not the one from the previous version.
Cream paper is thicker: the same book gets a spine about 11% wider than on white paper. It's the usual choice for fiction because it's easier on the eyes; white is more common for nonfiction with charts or photos.
A full worked example
A 6" × 9" novel with 300 pages, black-and-white interior on cream paper:
- Spine: 300 × 0.0025" = 0.75" (19.05 mm).
- Full width: 0.125 + 6 + 0.75 + 6 + 0.125 = 13" (330.2 mm).
- Full height: 0.125 + 9 + 0.125 = 9.25" (234.95 mm).
- At 300 DPI, the image has to be 3,900 × 2,775 pixels.
If at the last minute you add an epilogue and the interior grows to 316 pages, the spine becomes 0.79" and the whole cover has to be redone: the front panel shifts right by about a millimeter and the spine text ends up off-center. It's one of the most common reasons for rejection, and it almost always comes from a last-minute change to the interior.
Quick table: cover size by trim size
This table gives you the full height and the full width without the spine, with bleed already included. To get the final width, add the spine you get from the table above.
| Trim size | In centimeters | Full cover height | Width without spine |
|---|---|---|---|
| 5" × 8" | 12.7 × 20.32 | 8.25" (209.6 mm) | 10.25" (260.4 mm) |
| 5.25" × 8" | 13.34 × 20.32 | 8.25" (209.6 mm) | 10.75" (273.1 mm) |
| 5.5" × 8.5" | 13.97 × 21.59 | 8.75" (222.3 mm) | 11.25" (285.8 mm) |
| 5.83" × 8.27" (A5) | 14.8 × 21 | 8.52" (216.4 mm) | 11.91" (302.5 mm) |
| 6" × 9" | 15.24 × 22.86 | 9.25" (235 mm) | 12.25" (311.2 mm) |
| 7" × 10" | 17.78 × 25.4 | 10.25" (260.4 mm) | 14.25" (362 mm) |
| 8.5" × 11" | 21.59 × 27.94 | 11.25" (285.8 mm) | 17.25" (438.2 mm) |
If you work in pixels, multiply the inches by 300. A 6" × 9" cover with 300 pages on white paper, for example, is 12.93" × 9.25", which is about 3,878 × 2,775 pixels.
KDP has an official cover calculator that gives you a template as a PDF and a PNG with these lines already drawn. Use it even if you've done the math: it's the reference your file will be checked against.
Safe zone, spine text and barcode
With the overall dimensions sorted, three areas cause more trouble than they seem to.
The safe zone. On top of the bleed that gets trimmed off, KDP asks for text and important elements to stay at least 0.125" (3.2 mm) inside the trim line. That's the minimum; we recommend about 0.25" (6 mm). A title that grazes the edge looks careless even if it technically fits, and if the cut drifts slightly, it shows.
Spine text. KDP doesn't allow text on the spine if the book has 79 pages or fewer: the spine is around 0.2" wide and any drift in the fold would push the letters onto the front cover. From 80 pages you can, but leave at least 0.0625" (1.6 mm) clear on each side of the text. And don't design anything that depends on the fold landing exactly on a line: a band of color that ends right at the edge of the spine can peek onto the front if the fold shifts a couple of millimeters. It's safer to let the spine color run slightly onto the front and back.
The barcode. If you don't add your own, KDP prints one for free in the bottom-right corner of the back cover, in a 2" × 1.2" (50.8 × 30.5 mm) box. Keep that area clear of text and important images. If your blurb runs into it, the barcode will cover the last line.
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Hardcover: a different template, not the same one stretched
If you're also publishing a hardcover, don't adapt the paperback cover. The hardcover one is printed to wrap around board: it has a much wider wrap margin, about 0.6" (15 mm), that folds behind the boards, and a hinge area on each side of the spine where you shouldn't put anything important. The spine is calculated differently too, and KDP hardcovers require at least 75 pages.
The safe route is to download the hardcover template from KDP's cover calculator with your exact page count and build the design on top of it. If you're still unsure whether it's worth it, we ran the numbers in our guide to hardcover on Amazon KDP.
Make it work small: the design that sells
A cover can meet every measurement and still not sell. On Amazon, the first contact with your book is almost never the full-size cover but a thumbnail a couple of centimeters wide in the search results, surrounded by twenty others. That's where readers decide whether to click.
A few rules that work in almost every genre:
- Do the thumbnail test. Shrink the cover to 150 pixels wide and look at it from an arm's length away. If you can't read the title, it's too small or lacks contrast. If you can't make out the image, it has too many elements.
- Respect genre conventions. A thriller, a romance and a self-help book are recognizable at a glance from their typography, colors and composition. Before designing, look at the top 20 covers in your Amazon category. Not to copy them, but so readers instantly know what kind of book yours is.
- One main image. One object, one figure or one landscape, not five. What looks rich at full size becomes noise when small.
- Few words, set large. The title and your name. Subtitles and taglines are rarely readable in the thumbnail; if you include them, they shouldn't compete with the title.
- Check it in black and white. Many Kindle devices have e-ink screens, and readers will see your cover in shades of gray in their library. Red text on green might end up as the same gray.
How to make your KDP book cover, step by step
This is the order that saves you from redoing the cover twice:
- Finalize the interior before touching the cover. Format the book in its final trim size and export the final PDF. Until you have the exact page count, any print cover is provisional.
- Check the page count and page size. See how many pages the PDF has and make sure they're all the same size. Our KDP manuscript checker tells you in seconds, without uploading the file to any server.
- Calculate the spine and the full dimensions. With the page count and paper type, apply the formula or use KDP's cover calculator to download the template.
- Design the front with the thumbnail in mind. Front panel first, with a large title and a single main image. Then the spine and the back cover, with your blurb and the barcode area left clear.
- Export a single-page PDF at 300 DPI. With fonts embedded, layers flattened and the template guides removed. Separately, export the front as a 1,600 × 2,560 pixel JPG for the ebook.
- Review KDP's previewer before approving. It flags anything outside the safe area and anything that crosses into the spine. Order a proof copy too: holding the book reveals problems you can't see on screen.
Your options for making the cover, compared
There isn't one right option for everyone. It depends on your budget, how much control you want and how many books you plan to publish.
| Option | Approximate cost | Pros | Cons |
|---|---|---|---|
| Design it yourself in a graphics tool | Free or a subscription | Full control | You do the math and learn the tool |
| KDP Cover Creator | Free | Calculates the dimensions for you | Generic templates, limited design freedom |
| Premade cover | From about $50 | Fast and professional-looking | Not made for your story; other authors may have a similar one |
| Custom professional designer | From $200 to several hundred | Best result if you choose well | Price and turnaround; every page-count change means asking for a new spine |
| YourNovel Cover Designer | Included in paid plans | KDP dimensions calculated for you, AI or your own image | Built for authors writing their book in YourNovel |
One caveat that applies to every option: if your cover image is AI-generated, KDP asks when you publish whether your book contains AI-generated content, and that includes images. Answer truthfully. We cover it in detail in our guide to KDP's policy on books made with AI.
How YourNovel handles it
If you write your book in YourNovel.app, the cover comes from the same place as the book. Paid plans include a Cover Designer built around KDP's specs:
- You pick paperback or hardcover, the trim size (six for paperback, from 5" × 8" to 8.5" × 11"; three for hardcover), the paper type (white, cream or color) and the page count, and the designer calculates the spine and the full cover size instantly, in inches and millimeters.
- It applies the 0.125" bleed and shows the trim lines and safe zone on screen, so you don't have to guess where the usable area ends.
- You generate the image with AI by describing it in your own words, or upload your own.
- You add the title, subtitle and your name; on the back, your blurb and, if you want, the barcode. Spine text only unlocks from 80 pages, as KDP requires.
- You download the full cover (back, spine and front) as a 300 DPI PDF at the exact dimensions, or the front panel alone.
Best of all, if your page count changes, you move one slider and the cover recalculates itself. No need to ask anyone for a new file.
For hardcover, the designer adds the 15 mm that wraps around the board, widens the spine and marks in orange the 10 mm hinge on each side, where text must not go. Even so, compare the dimensions with KDP's hardcover template before uploading: it's the reference your file is checked against. And for the ebook, the front panel gives you the base for preparing the JPG.
Why KDP rejects a cover
These are the reasons we see most often, almost all easy to avoid if you know them in advance:
- The spine doesn't match the interior. You changed the page count after making the cover, or made it for white paper and chose cream on KDP.
- Text outside the safe zone. The title or author name too close to the edge.
- Spine text with 79 pages or fewer. KDP doesn't allow it.
- Missing bleed. The image is exactly the size of the book, without the extra 0.125" on each side.
- Template lines left in the PDF. The colored guides in KDP's template are for designing, not for printing.
- Low resolution. A 72 DPI image scaled up will look pixelated on paper even if it looks fine on screen.
- Title or author don't match the book details. What the cover says has to match what you entered on KDP. If you're filling in those details, our guide to Amazon KDP keywords and categories will help.
- Prices, promotions or Amazon references on the cover. The cover can't advertise prices or promotions like "free on Kindle Unlimited", or use Amazon logos.
Frequently asked questions
What size should a Kindle ebook cover be on Amazon KDP? The recommended size is 1,600 pixels wide by 2,560 pixels tall, as a JPG or TIFF in RGB. The minimum is 625 × 1,000 pixels and the maximum is 10,000 pixels on the long side and 50 MB.
How do I calculate my book's spine width? Multiply the page count of your final interior by the paper thickness: 0.002252" per page on white paper and 0.0025" on cream paper. A 200-page book on cream paper has a 0.5" (12.7 mm) spine.
How much bleed does KDP require? 0.125" (3.2 mm) on every outer edge of the cover. There's no bleed between the front cover, the spine and the back cover.
How many pages do I need for spine text? More than 79. With 80 pages or more you can put the title and author on the spine, leaving at least 0.0625" (1.6 mm) clear on each side.
Can I use the same image for the ebook and the paperback? Yes, and it's recommended so readers recognize the book. But they're two different files: the ebook is just the front as a JPG, and the paperback is the full cover as a PDF with bleed.
Can I use an AI-generated image on my cover? Yes. KDP allows it, but asks whether your book contains AI-generated content, and that includes cover images. You have to disclose it.
What happens if I change the page count after uploading the cover? You have to redo the cover with the new spine and upload it again. KDP compares the cover width with the interior and rejects it if they don't match.
The cover is the first thing readers see, and the last thing authors fix
It's funny: the cover is the first thing a reader sees and usually the last thing an author does, in a hurry, with the book already finished. That's why it causes so much trouble. If you keep one idea from this guide, make it this: the print cover depends on the interior, so finalize the interior first, count the pages carefully and let the measurements follow from there.
If you're still writing your book, YourNovel.app takes you from the first idea to the interior PDF and the full KDP cover without switching tools, with the spine calculated from your pages. And if your book is already done, run the PDF through the manuscript checker first so you know exactly how many pages you're working with. The rest is arithmetic.