KDP Cover Size & Spine Width Calculator
Pick your trim size, page count and paper. Get the exact cover size, spine width and a 300 DPI template to give your designer.
The finished size of your book.
Every page in the interior file, blanks included.
Cream paper is thicker, so it makes a wider spine.
Your paperback cover
Full cover size, with bleed
13 × 9.25 in
3,900 × 2,775 px at 300 DPI.
Spine width
0.75 in
Bleed
0.125 in
Each outside edge.
- Bleed. Trimmed off. Extend your art into it.
- Trim line. Where the cover is cut.
- Safe zone. Keep text inside.
- Spine folds. Where the cover bends.
- Barcode. KDP prints it here.
The PNG is 300 DPI at full size. Put it on a top layer in your design app as a guide, then hide it before you export.
Exact numbers
- Full cover, with bleed
- 13 × 9.25 in
- Spine width300 × 0.0025 in per page
- 0.75 in
- Front and back coverYour trim size, each
- 6 × 9 in
- BleedTop, bottom and both outside edges
- 0.125 in
- At 300 DPI
- 3,900 × 2,775 px
- Text safe marginInside every trim line
- 0.125 in
- Spine text area0.0625 in clear of each fold
- 0.625 in
- Barcode areaBottom right of the back
- 2 × 1.2 in
Rules as of November 2026
Cover sorted? Give it a home. Your free author site lives at authorpage.me/yourname.
Make your book pageFree to use. What you type stays in your browser.
How it works
Step 1: Pick your trim size
Choose one of KDP's paperback sizes, or enter a custom size. 6 × 9 in is the most common for novels.
Step 2: Enter your page count and paper
Use the page count of your final interior file. Cream paper is thicker than white, so the spine grows.
Step 3: Copy the specs or download the template
Send the numbers to your designer, or drop the PNG or SVG template into your design app as a guide layer.
How to calculate spine width for a KDP paperback
Your spine width is your page count times the thickness of one page. KDP gives a number for each paper. White paper adds 0.002252 in per page. Cream adds 0.0025 in. Premium color adds 0.002347 in, and standard color adds 0.002252 in. So a 300-page novel on cream paper has a 0.75 in spine. On white paper it's 0.676 in.
Use the page count from your final interior PDF, blanks and front matter included. If you add a chapter or change the font size later, your page count changes and so does the spine. Work out the cover last, once the interior is locked.
KDP paperback cover dimensions
A paperback cover is one flat image that wraps around the book. From left to right it goes back cover, spine, front cover. KDP adds 0.125 in of bleed on the top, bottom and both outside edges. So the full width is two times your trim width, plus the spine, plus 0.25 in. The full height is your trim height plus 0.25 in.
Here is what that looks like for a 6 × 9 in book on cream paper:
| Page count | Spine width | Full cover size | At 300 DPI |
|---|---|---|---|
| 150 | 0.375 in | 12.625 × 9.25 in | 3,788 × 2,775 px |
| 250 | 0.625 in | 12.875 × 9.25 in | 3,863 × 2,775 px |
| 350 | 0.875 in | 13.125 × 9.25 in | 3,938 × 2,775 px |
| 450 | 1.125 in | 13.375 × 9.25 in | 4,013 × 2,775 px |
What bleed means on a book cover
Printers can't cut paper perfectly. Each cover can shift a little on the trimmer. Bleed is extra artwork past the cut line, so that shift never leaves a thin white edge. Stretch your background image or color all the way to the outer edge of the template. Don't put anything you need to keep in the bleed, because it gets cut off.
Where to put text, the spine title and the barcode
- Cover text: keep it at least 0.125 in inside the trim line. More room looks better, and 0.25 in is a comfortable margin for titles and author names.
- Spine text: KDP only allows it from 79 pages (Cover Creator needs 80). Leave 0.0625 in between your text and each fold, because the fold can drift a little.
- Barcode: KDP prints it for free in a 2 × 1.2 in box at the bottom right of the back cover. Keep that corner clear of text and faces.
- Resolution: export at 300 DPI as a PDF. A 6 × 9 in cover needs roughly 3,900 × 2,800 px.
Paperback vs hardcover cover size
This calculator is for paperbacks. A KDP hardcover uses a case wrap, which folds over thick boards. It needs a wider wrap area, a hinge gap on each side of the spine, and a different spine width for the same page count. If you're making a hardcover, download the template from KDP's own cover calculator and pick "Hardcover".
Once your cover is ready, make a 3D image of it for your ads with our book mockup generator. Then give the book a home on your own author website, with buy links for every store.
Questions authors ask
Two times your trim width, plus your spine width, plus 0.25 in for bleed. The height is your trim height plus 0.25 in. A 6 × 9 in book with 300 pages on cream paper needs a 13 × 9.25 in cover.